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ARTICLES OF INTEREST

The following listings are links to articles I have found on the web that may, or may not, be of interest to you, the gentle reader out there. I think that these are orticles that one may not easily find just surfing the web, as it is usually a serendipitous thing when I come across them.

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Select Publication Nature National Geographic News Science Science Daily Science News Smithsonian Magazine Other Sources

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Nature
Nature requires that you register and login in order to see any articles or abstracts. Not all articles are available for free, you need to subscribe to see all articles. Those that are not available for free will be marked with a "$$"

An artificial landscape-scale fishery in the Bolivian Amazon
CLARK L. ERICKSON
Historical ecologists working in the Neotropics argue that the present natural environment is an historical product of human intentionality and ingenuity, a creation that is imposed, built, managed and maintained by the collective multigenerational knowledge and experience of Native Americans^{1, 2}. In the past 12,000 years, indigenous peoples transformed the environment, creating what we now recognize as the rich ecological mosaic of the Neotropics^3-6. The prehispanic savanna peoples of the Bolivian Amazon built an anthropogenic landscape through the construction of raised fields, large settlement mounds, and earthen causeways^{7, 8}. I have studied a complex artificial network of hydraulic earthworks covering 525 km² in the Baures region of Bolivia. Here I identify a particular form of earthwork, the zigzag structure, as a fish weir, on the basis of form, orientation, location, association with other hydraulic works and ethnographic analogy. The native peoples used this technology to harvest sufficient animal protein to sustain large and dense populations in a savanna environment. (Nature 408, 190 - 193 (2000).)

$$ "Biodiversity As A Barrier To Ecological Invasion" $$
Theodore A. Kennedy, Shahid Naeem, Katherine M. Howe, Johannes M. H. Knops, David Tilman & Peter Reich
Biological invasions are a pervasive and costly environmental problem that has been the focus of intense management and research activities over the past half century. Yet accurate predictions of community susceptibility to invasion remain elusive. The diversity resistance hypothesis, which argues that diverse communities are highly competitive and readily resist invasion, is supported by both theory and experimental studies conducted at small spatial scales. However, there is also convincing evidence that the relationship between the diversity of native and invading species is positive when measured at regional scales. Although this latter relationship may arise from extrinsic factors, such as resource heterogeneity, that covary with diversity of native and invading species at large scales, the mechanisms conferring greater invasion resistance to diverse communities at local scales remain unknown. Using neighbourhood analyses, a technique from plant competition studies, we show here that species diversity in small experimental grassland plots enhances invasion resistance by increasing crowding and species richness in localized plant neighbourhoods. Both the establishment (number of invaders) and success (proportion of invaders that are large) of invading plants are reduced. These results suggest that local biodiversity represents an important line of defence against the spread of invaders. (Nature 417, 636 - 638 (2002).
$$ "Copepod Hatching Success In Marine Ecosystems With High Diatom Concentrations" $$
Xabier Irigoien, Roger P. Harris, Hans M. Verheye, Pierre Joly, Jeffrey Runge, Michel Starr, David Pond, Robert Campbell, Rachael Shreeve, Peter Ward, Amy N. Smith, Hans G. Dam, William Peterson, Valentina Tirelli, Marja Koski, Tania Smith, Derek Harbour & Russell Davidson
Diatoms dominate spring bloom phytoplankton assemblages in temperate waters and coastal upwelling regions of the global ocean. Copepods usually dominate the zooplankton in these regions and are the prey of many larval fish species. Recent laboratory studies suggest that diatoms may have a deleterious effect on the success of copepod egg hatching. These findings challenge the classical view of marine food-web energy flow from diatoms to fish by means of copepods. Egg mortality is an important factor in copepod population dynamics, thus, if diatoms have a deleterious in situ effect, paradoxically, high diatom abundance could limit secondary production. Therefore, the current understanding of energy transfer from primary production to fisheries in some of the most productive and economically important marine ecosystems may be seriously flawed. Here we present in situ estimates of copepod egg hatching success from twelve globally distributed areas, where diatoms dominate the phytoplankton assemblage. We did not observe a negative relationship between copepod egg hatching success and either diatom biomass or dominance in the microplankton in any of these regions. The classical model for diatom-dominated system remains valid.
$$ "Cells compete for Decapentaplegic survival factor to prevent apoptosis in Drosophila wing development" $$
Eduardo Moreno, Konrad Basler & Ginés Morata.
During the growth of Drosophila imaginal discs a process called 'cell competition' eliminates slow-proliferating but otherwise viable cells. We report here that cell competition requires the function of the brinker (brk) gene, whose expression is normally repressed by Decapentaplegic (Dpp) signalling but is upregulated in slow- growing Minute/+ cells. Excess brk expression activates the c-Jun amino-terminal kinase pathway, which in turn triggers apoptosis in these cells. We propose that slow- proliferating cells upregulate Brk levels owing to a disadvantage in competing for, or in transducing, the Dpp survival signal. This sequence of events might represent a general mechanism by which weaker cells are eliminated from a growing population, and might serve as a method of controlling cell number and optimizing tissue fitness and hence organ function. (Nature 416, 755 - 759 (2002)).
$$ "Endoscopic exploration of Red Sea coral reefs reveals dense populations of cavity-dwelling sponges" $$
ClaudioÝRichter, MarkÝWunsch, MohammedÝRasheed, IrisÝKÖtter & MohammadÝI.ÝBadran
Framework cavities are the largest but least explored coral reef habitat. Previous dive studies of caverns, spaces below plate corals, rubble and artificial cavities suggest that cavity-dwelling (coelobite) filter-feeders are important in the trophodynamics of reefs. Quantitative community data are lacking, however, as the bulk of the narrow crevices interlacing the reef framework are inaccessible to conventional analysis methods. Here we have developed endoscopic techniques to explore Red Sea framework crevices up to 4Ým into the carbonate rock, revealing a large internal surface (2.5ñ7.4Ým2 per projectedÝm2 reef) dominated by encrusting filter-feeders. Sponges alone provided up to 60% of coelobite cover, outweighing epi-reefal filter-feeder biomass by two orders of magnitude. Coelobite community filtration removed more than 60% of the phytoplankton in the course of its less than 5-minute passage through the crevices, corresponding to an uptake of roughly 0.9ÝgÝcarbonÝm-2Ýd-1. Mineralization of the largely allochthonous organic material is a principal source of nutrients supporting coral and algal growth. The supply of new material by coelobites may provide a key to understanding the 'coral reef paradox'óa rich ecosystem thriving in nutrient-poor water.
$$"Fin development in a cartilaginous fish and the origin of vertebrate limbs"$$
MIKIKO TANAKA, ANDREA M?NSTERBERG, W. GARY ANDERSON, ALAN R. PRESCOTT, NEIL HAZON & CHERYLL TICKLE
Recent fossil finds and experimental analysis of chick and mouse embryos highlighted the lateral fin fold theory, which suggests that two pairs of limbs in tetrapods evolved by subdivision of an elongated single fin. Here we examine fin development in embryos of the primitive cartilaginous fish, Scyliorhinus canicula (dogfish) using scanning electron microscopy and investigate expression of genes known to be involved in limb positioning, identity and patterning in higher vertebrates. Although we did not detect lateral fin folds in dogfish embryos, Engrailed-1 expression suggests that the body is compartmentalized dorso- ventrally. Furthermore, specification of limb identity occurs through the Tbx4 and Tbx5 genes, as in higher vertebrates. In contrast, unlike higher vertebrates, we did not detect Shh transcripts in dogfish fin-buds, although dHand (a gene involved in establishing Shh) is expressed. In S. canicula, the main fin axis seems to lie parallel to the body axis. 'Freeing' fins from the body axis and establishing a separate 'limb' axis has been proposed to be a crucial step in evolution of tetrapod limbs. We suggest that Shh plays a critical role in this process. (Nature 416, 527 - 531 (2002).)
"Fossil evidence of water lilies (Nymphaeales) in the Early Cretaceous"
ELSE MARIE FRIIS, KAJ RAUNSGAARD PEDERSEN & PETER R. CRANE
Phylogenetic analyses have identified the water lilies (Nymphaeales: Cabombaceae and Nymphaeaceae), together with four other small groups of flowering plants (the 'ANITA clades': Amborellaceae, Illiciales, Trimeniaceae, Austrobaileyaceae), as the first diverging lineages from the main branch of the angiosperm phylogenetic tree, but evidence of these groups in the earliest phases of the angiosperm fossil record has remained elusive. Here we report the earliest unequivocal evidence, based on fossil floral structures and associated pollen, of fossil plants related to members of the ANITA clades. This extends the history of the water lilies (Nymphaeales) back to the Early Cretaceous (125ñ115 million years) and into the oldest fossil assemblages that contain unequivocal angiosperm stamens and carpels. This discovery adds to the growing congruence between results from molecular-based analyses of relationships among angiosperms and the palaeobotanical record. It is also consistent with previous observations that the flowers of early angiosperms were generally very small compared with those of their living relatives.
"Growth of domesticated transgenic fish"
Robert H. Devlin, Carlo A. Biagi, Timothy Y. Yesaki, Duane E. Smailus & John C. Byatt
A growth-hormone transgene boosts the size of wild but not domesticated trout.
$$ "Large-amplitude cycles of Daphnia and its algal prey in enriched environments"
EDWARD MCCAULEY, ROGER M. NISBET, WILLIAM W. MURDOCH, ANDRE M. DE ROOS & WILLIAM S. C. GURNEY
Ecological theory predicts that stable populations should yield to large-amplitude cycles in richer environments. This does not occur in nature. The zooplankton Daphnia and its algal prey in lakes throughout the world illustrate the problem. Experiments show that this system fits the theory's assumptions, yet it is not destabilized by enrichment. We have tested and rejected four of five proposed explanations. Here, we investigate the fifth mechanism: inedible algae in nutrient-rich lakes suppress cycles by reducing nutrients available to edible algae. We found three novel results in nutrient-rich microcosms from which inedible algae were excluded. First, as predicted by theory, some Daphnia-edible algal systems now display large-amplitude predator-prey cycles. Second, in the same environment, other populations are stable, showing only small-amplitude demographic cycles. Stability is induced when Daphnia diverts energy from the immediate production of young. Third, the system exhibits coexisting attractorsóa stable equilibrium and large-amplitude cycle. We describe a mechanism that flips the system between these two states. (Nature 402, 653 - 656 (1999).)
$$ "Future projections for Mexican faunas under global climate change scenarios" $$
A. TOWNSEND PETERSON, MIGUEL A. ORTEGA-HUERTA, JEREMY BARTLEY, VICTOR SÁNCHEZ-CORDEROß, JORGE SOBERÓN, ROBERT H. BUDDEMEIER & DAVID R. B. STOCKWELL
Global climates are changing rapidly, with unexpected consequences. Because elements of biodiversity respond intimately to climate as an important driving force of distributional limitation, distributional shifts and biodiversity losses are expected. Nevertheless, in spite of modelling efforts focused on single species or entire ecosystems, a few preliminary surveys of fauna-wide effects, and evidence of climate change-mediated shifts in several species, the likely effects of climate change on species' distributions remain little known, and fauna-wide or community-level effects are almost completely unexplored. Here, using a genetic algorithm and museum specimen occurrence data, we develop ecological niche models for 1,870 species occurring in Mexico and project them onto two climate surfaces modelled for 2055. Although extinctions and drastic range reductions are predicted to be relatively few, species turnover in some local communities is predicted to be high (>40% of species), suggesting that severe ecological perturbations may result. (Nature 416, 626 - 629 (2002))
$$ "Marine control of biological production in the eastern equatorial Pacific Ocean"
PAUL LOUBERE
The eastern equatorial Pacific Ocean is the site of approximately 20ñ50% of new biological production in the global oceans. This region is also responsible for the greatest efflux of CO₂ from oceans to the atmosphere. New production, which fixes carbon in response to external inputs of nutrients as opposed to supply from local nutrient recycling, is thought to modulate the CO₂ release. But what controls new production in this region is less clear. Here we present a quantitative reconstruction of biological production in the surface ocean for this region over the past 130,000 years, which shows that the equatorial Pacific Ocean exhibits higher-frequency variations than the South Equatorial Current. Comparison of these records with palaeotemperature reconstructions indicates that atmospherically driven mechanismsósuch as aeolian flux of iron or wind-driven changes in upwelling rate of nutrient-rich watersóare unlikely to have influenced longer-term rates of production in this region. Instead, biological production appears to be governed by changes in ocean circulation and the chemical composition of upwelled water. (Nature 406, 497 - 500 (2000).)
$$ "Marine ecology: Bleaching patterns in reef corals"
B. E. BROWN, R. P. DUNNE, M. S. GOODSON & A. E. DOUGLAS
Coral reefs are under threat from the effects of bleaching, in which symbiotic algae or their photosynthetic pigments are destroyed by increased sea temperatures and solar radiation. Here we show that the bleaching susceptibility of Goniastrea aspera, a shallow-water Indo-Pacific coral, can be predicted from its history of exposure to solar radiation, demonstrating how experience can shape coral bleaching patterns. (Nature 404, 142 - 143 (2000).)
$$ "Mesoscale vertical motion and the size structure of phytoplankton in the ocean" $$
JAIME RODRÍGUEZ, JOAQUÍN TINTORÉ, JOHN T. ALLEN, JOSÉ MA BLANCO, DAMIÀ GOMIS, ANDREAS REUL, JAVIER RUIZ, VALERIANO RODRÍGUEZ, FIDEL ECHEVARRÍA & FRANCISCO JIMÉNEZ-GÓMEZ
Phytoplankton size structure is acknowledged as a fundamental property determining energy flow through 'microbial' or 'herbivore' pathways. The balance between these two pathways determines the ability of the ecosystem to recycle carbon within the upper layer or to export it to the ocean interior. Small cells are usually characteristic of oligotrophic, stratified ocean waters, in which regenerated ammonium is the only available form of inorganic nitrogen and recycling dominates. Large cells seem to characterize phytoplankton in which inputs of nitrate enter the euphotic layer and exported production is higher. But the size structure of phytoplankton may depend more directly on hydrodynamical forces than on the source of available nitrogen. Here we present an empirical model that relates the magnitude of mesoscale vertical motion to the slope of the sizeñabundance spectrum of phytoplankton in a frontal ecosystem. Our model indicates that the relative proportion of large cells increases with the magnitude of the upward velocity. This suggests that mesoscale vertical motionóa ubiquitous feature of eddies and unstable frontsócontrols directly the size structure of phytoplankton in the ocean.
$$ "Modern freshwater microbialite analogues for ancient dendritic reef structures"
BERNARD LAVAL, SHERRY L. CADY, JOHN C. POLLACK, CHRISTOPHER P. MCKAY, JOHN S. BIRD, JOHN P. GROTZINGER, DEREK C. FORD & HARRY R. BOHM
Microbialites are organosedimentary structures that can be constructed by a variety of metabolically distinct taxa. Consequently, microbialite structures abound in the fossil record, although the exact nature of the biogeochemical processes that produced them is often unknown. One such class of ancient calcareous structures, Epiphyton and Girvanella, appear in great abundance during the Early Cambrian. Together with Archeocyathids, stromatolites and thrombolites, they formed major Cambrian reef belts. To a large extent, Middle to Late Cambrian reefs are similar to Precambrian reefs, with the exception that the latter, including terminal Proterozoic reefs, do not contain Epiphyton or Girvanella. Here we report the discovery in Pavilion Lake, British Columbia, Canada, of a distinctive assemblage of freshwater calcite microbialites, some of which display microstructures similar to the fabrics displayed by Epiphyton and Girvanella. The morphologies of the modern microbialites vary with depth, and dendritic microstructures of the deep water (>30 m) mounds indicate that they may be modern analogues for the ancient calcareous structures. These microbialites thus provide an opportunity to study the biogeochemical interactions that produce fabrics similar to those of some enigmatic Early Cambrian reef structures. (Nature 407, 626 - 629 (2000))
$$ "A primitive fish close to the common ancestor of tetrapods and lungfish" $$
Min Zhu and Xiaobo Yu
The relationship of the three living groups of sarcopterygians or lobe-finned fish (tetrapods, lungfish and coelacanths) has been a matter of debate. Although opinions still differ, most recent phylogenies suggest that tetrapods are more closely related to lungfish than to coelacanths. However, no previously known fossil taxon exhibits a concrete character combination approximating the condition expected in the last common ancestor of tetrapods and lungfishóand it is still poorly understood how early sarcopterygians diverged into the tetrapod lineage (Tetrapodomorpha) and the lungfish lineage (Dipnomorpha). Here we describe a fossil sarcopterygian fish, Styloichthys changae gen. et sp. nov., that possesses an eyestalk and which exhibits the character combination expected in a stem group close to the last common ancestor of tetrapods and lungfish. Styloichthys from the Lower Devonian of China bridges the morphological gap between stem-group sarcopterygians (Psarolepis and Achoania) and basal tetrapodomorphs/basal dipnomorphs. It provides information that will help in the study of the relationship of early sarcopterygians, and which will also help to resolve the tetrapodñlungfish divergence into a documented sequence of character acquisition. (Nature 418, 767 - 770 (2002))
$$ "The relative influences of nitrogen and phosphorus on oceanic primary production"
TOBY TYRRELL
A simple model has the potential to resolve the long-running debate amongst oceanographers over whether nitrogen or phosphorus exerts overall control on oceanic primary production. A representation of the competition between nitrogen-fixing and other phytoplankton is inserted into a two-box global model of the oceanic nitrogen and phosphorus cycles. Homeostatic regulation of both nitrate and phosphate concentrations results, with surface waters more deficient in nitrate than phosphate in the steady state, but with external phosphate inputs controlling longer-term primary production in the global ocean. (Nature 400, 525 - 531 (1999).)
$$ "Site of particle selection in a bivalve mollusc"
J. EVAN WARD, JEFFREY S. LEVINTON, SANDRA E. SHUMWAY & TERRY CUCCI
Bivalve molluscs form dense populations that exert profound effects on the particle loads and phytoplankton composition of coastal waters. It has long been known that bivalves can select among different particle types, including selecting against those of poor nutritional value, but because of difficulties in observing particle transport processes in the pallial cavity in vivo, the mechanism of selection was not known. We now use a combination of video endoscopy and flow cytometry to show that oysters can select living particles from non-living detritus on the gills. Our methods could aid the study of suspension feeding in many animal groups. (Nature 390, 131 - 132 (1997).)

NATURE GENETICS

[link opens in new window]$$ ""Cardiomyopathy In Zebrafish Due To Mutation In An Alternatively Spliced Exon Of Titin" $$
Xiaolei Xu, Steffen E. Meiler1, Tao P. Zhong, Manzoor Mohideen, Dane A. Crossley, Warren W. Burggren & Mark C. Fishman.
The zebrafish embryo is transparent and can tolerate absence of blood flow because its oxygen is delivered by diffusion rather than by the cardiovascular system¹. It is therefore possible to attribute cardiac failure directly to particular genes by ruling out the possibility that it is due to a secondary effect of hypoxia. We focus here on pickwick^m171 (pik^m171), a recessive lethal mutation discovered in a large-scale genetic screen². There are three other alleles in the pik complementation group with this phenotype (pik^m242, pik^m740, pik^m186; ref. 3) and one allele (pik^mVO62H) with additional skeletal paralysis⁴. The pik heart develops normally but is poorly contractile from the first beat. Aside from the edema that inevitably accompanies cardiac dysfunction, development is normal during the first three days. We show by positional cloning that the 'causative' mutation is in an alternatively-spliced exon of the gene (ttn) encoding Titin. Titin is the biggest known protein and spans the half-sarcomere from Z-disc to M-line in heart and skeletal muscle⁵. It has been proposed to provide a scaffold for the assembly of thick and thin filaments⁶ and to provide elastic recoil engendered by stretch during diastole⁷. We found that nascent myofibrils form in pik mutants, but normal sarcomeres are absent. Mutant cells transplanted to wildtype hearts remain thin and bulge outwards as individual cell aneurysms without affecting nearby wildtype cardiomyocytes, indicating that the contractile deficiency is cell- autonomous. Absence of Titin function thus results in blockage of sarcomere assembly and causes a functional disorder resembling human dilated cardiomyopathies, one form of which is described in another paper in this issue⁸. (Nature Genetics --Published online: 14 January 2002, DOI:10.1038/ng816 volume 30 no. 2 pp 205 - 209.)
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National Geographic News

Alien Invasion: Exotic Species Sow Destruction Across the Atlantic
In less than ten years, non-native zebra mussels that were stowaways on ships from Europe have infested America's waterways, clogging inlets and pushing local species of freshwater shellfish to extinction.

Over the same period, America's western corn rootworm hitched a ride on a commercial flight to Belgrade and has since been munching the heart out of Europe's farmland.

And in the U.S. Everglades, a noxious pest plant from Australia called the melaleuca tree is crowding out native vegetation, prompting scientists to import predator bugs from Australia in an effort to curb the spread.

These pests are prime examples of how global trade has spread invasive species around the world, sometimes grossly upsetting the balance of nature. Introduced species often find no natural enemies in their new habitat. They spread easily and quickly, many times ousting native species.
(National Geographic News, September 24, 2001.)
"Atlantic Sturgeon Cling to Life in Virginia River"
The Atlantic sturgeon, a bone-plated behemoth that once kept company with dinosaurs, is clinging to life in the James River. The menacing-looking but harmless fish, which can exceed 10 feet in length, is so rare some experts say it's extinct in Virginia. In recent years, however, scientists have found hundreds of young sturgeons, and a handful of six- to eight-foot adults.
"Biggest Ever U.S. Fish Study Aids Florida Conservation"
Dahleen Glanton, Chicago Tribune, July 30, 2002
In the most ambitious study of marine life ever undertaken in the United States, scientists spent a month recently counting the fish in the Florida Keys, from the waters south of Miami to the coral forests beyond Key West.
Brittle Star Found Covered With Optically Advanced "Eyes"
In a clever twist of nature, the sea has eyes in its stars.
Scientists have discovered a species of brittle star whose outer skeleton is covered with crystalline lenses that appear to work collectively as an all- seeing eye. (National Geographic News, August 22, 2001.)
Camera-Fitted Seals Spy Antarctic Sea Life
Bijal P. Trivedi, National Geographic Today, January 23, 2002
By mounting video cameras on the heads of Weddell seals in Antarctic seas, scientists have gained much insight into the life of the seals. But the technique also provides another unexpected bounty: a rare spy's-eye look at species the seals prey on.
Coral Reef Paradise Found in Remote Indonesian Islands
John Roach for National Geographic News, August 8, 2001.
Scuba divers, take note: The waters of the Raja Ampat Islands off Indonesia's province of Irian Jaya may replace heralded Palau as the most species-rich sea in the world.
"Cod 'Fingerprinting' May Aid Conservation"
Bijal P. Trivedi for National Geographic Today, September 24, 2001.
Researchers have developed a way to "fingerprint" cod.
The technique, essentially a genetic identification tag, enables researchers to determine a specific cod's place of origin, which could be particularly useful in enforcing international fishing quotas and catching poachers.
"Explorers Pinpoint Source of the Amazon"
Donald Smith.
Long a subject of argument and speculation, the source of the Amazon River has now been pinpointed by a five-nation National Geographic expedition using state-of-the-art Global Positioning System (GPS) navigational gear. The point of origin is a trickle of water coming off a cliff high in the Peruvian Andes. (National Geographic News, December 21, 2000.)
"Reclaiming the Florida Everglades"
Donald Smith
Political unity is something that the state of Florida has not been winning any medals for recently. But for one shining moment just before this yearís presidential election, an unlikely combination of political bedfellows came together to approve what is being hailed as the most ambitious environmental project in U.S. history: a 20-year, $15.6-billion effort to restore the 4,000 square miles (10,000 square kilometers) of sawgrass and swamp that make up the Florida Everglades. (National Geographic News, December 13, 2000.)
Scientists Track Giant Sunfish by Satellite
David Braun
"The world's largest bony fish looks like a massive swimming head and is extremely gentle and curious," says Tierney Thys of the giant ocean sunfish, a sea creature that can grow to more than 4,000 pounds (1,800 kilograms). "Yet it is an animal we know very little about." (National Geographic News, February 2, 2001.
"South Africa Takes Urgent Steps to Avert Fishery Collapse"
Some linefish stocks have dropped to such low levels along South Africa's coast that the country's government is taking emergency steps to rebuild them.
"Tiny Mandarin Fish Reveal Surprisingly Complex Spawning Ritual"
Each year, more than 40 million fish are removed from the wild to fill the tanks of marine aquarium hobbyists. With the increasing popularity of reef aquariums, that number is likely to grow.
What this popularity means to ocean fish populations worries scientists and conservationists. There is a real danger that excessive removals of wild fish for the aquarium trade could have a devastating impact on local populations, said Yvonne Sadovy, a biologist at the University of Hong Kong.
Very little is known about the life cycles and biology of many reef species. This makes it difficult to determine whether the fish need to be protected, and if so, how.
To help provide answers, Sadovy, along with Mariella Rasotto from the University of Padova and George Mitcheson from the University of Hong Kong, have studied populations of exotically colored mandarin fish in Palau, Micronesia. The project was funded with assistance from the National Geographic Society's Committee for Research and Exploration.
"'Weird' New Squid Species Discovered in Deep Sea"
Bijal P. Trivedi, National Geographic Today, December 20, 2001
Deep-sea submersibles have spotted and filmed a new type of squid in the deep waters of the Gulf of Mexico, and the Pacific, Atlantic, and Indian Oceans.
"Why Is Seaweed Killing Florida's Coral Reefs?"
Bijal P. Trivedi National Geographic Today, August 23, 2001.
Scientists returned today from a ten-day underwater mission to find out more about a species of brown seaweed that is suffocating Florida's vibrant coral reefs.

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Science
$$"Bile Acid Secreted by Male Sea Lamprey That Acts as a Sex Pheromone"$$
Weiming Li, Alexander P. Scott, Michael J. Siefkes, Honggao Yan, Qin Liu, Sang-Seon Yun, Douglas A. Gage
We show that reproductively mature male sea lampreys release a bile acid that acts as a potent sex pheromone, inducing preference and searching behavior in ovulated female lampreys. The secreted bile acid 7,12,24- trihydroxy-5-cholan-3-one 24-sulfate was released in much higher amounts relative to known vertebrate steroid pheromones and may be secreted through the gills. Hence, the male of this fish species signals both its reproductive status and location to females by secreting a pheromone that can act over long distances. (Science--296 (5565):138 Issue of 5 Apr 2002.)
$$ "The Effect of Algal Symbionts on the Accuracy of Sr/Ca Paleotemperatures from Coral" $$
Anne L. Cohen, Kathryn E. Owens, Graham D. Layne, Nobumichi Shimizu
The strontium-to-calcium ratio (Sr/Ca) of reef coral skeleton is commonly used as a paleothermometer to estimate sea surface temperatures (SSTs) at crucial times in Earth's climate history. However, these estimates are disputed, because uptake of Sr into coral skeleton is thought to be affected by algal symbionts (zooxanthellae) living in the host tissue. Here, we show that significant distortion of the Sr/Ca temperature record in coral skeleton occurs in the presence of algal symbionts. Seasonally resolved Sr/Ca in coral without symbionts reflects local SSTs with a temperature sensitivity equivalent to that of laboratory aragonite precipitated at equilibrium and the nighttime skeletal deposits of symbiotic reef corals. However, up to 65% of the Sr/Ca variability in symbiotic skeleton is related to symbiont activity and does not reflect water temperature. (Science, Vol. 296, Issue 5566, 331-333, April 12, 2002)
$$ "Genetic Evidence for Local Retention of Pelagic Larvae in a Caribbean Reef Fish" $$
Michael S. Taylor, Michael E. Hellberg
The pelagic larvae of many marine organisms can potentially disperse across hundreds of kilometers, but whether oceanographic or behavioral mechanisms can constrain dispersal over periods sufficient for the evolution of genetic differentiation remains unclear. Here, we concurrently examine larval duration and genetic population differentiation in a cleaner goby, Elacatinus evelynae, a member of the most species-rich genus of Caribbean reef fishes. Despite evidence for extended pelagic duration (21 days), populations of E. evelynae show strong genetic differentiation: among color forms (1.36 to 3.04% divergent at mitochondrial cytochrome b) and among island populations within color forms (_ST up to 70%). These results suggest that marine populations can remain demographically closed for thousands of generations despite extended larval duration, and that recognition cues such as color may promote speciation when geographic barriers are transient or weak. (Science, Volume 299, Number 5603, Issue of 3 Jan 2003, pp. 107-109.)
$$ "Picturing the Perfect Preserve" $$
David Malakoff
A growing number of scientists are turning to new mapping software to help them design networks of marine reserves that are both politically viable and ecologically effective. The programs enable planners to test thousands of possible arrangements for achieving conservation goals, such as preserving fragile coral reefs or shielding vulnerable spawning fish from nets. Just as important, cybermapping may allow reserve advocates to sidestep potentially disastrous political conflicts by flagging areas where a protected zone might draw opposition from anglers or other economic interests. (Science, Vol. 296, Issue 5566, 245, Aprile 12, 2002.)
$$ "Why Gobies Are Like Hobbits" $$
Stephen R. Palumbi and Robert R. Warner
In the Caribbean waters around Puerto Rico, the blue and white forms of the goby fish live within 23 kilometers of each other yet remain genetically separate populations. This is surprising given that their pelagic larvae survive for 3 weeks and would be predicted to be dispersed by ocean currents over large distances (Taylor and Hellberg). In their Perspective, Palumbi and Warner discuss this discovery and comment on how the larvae manage to stay close to home. (Science, Volume 299, Number 5603, Issue of 3 Jan 2003, pp. 51-52.)

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Science Daily
"Africa's Lake Chad Shrinks By 20 Times Due To Irrigation Demands, Climate Change"
In the 1960s, North central Africa's Lake Chad was larger than the state of Vermont but is now smaller than Rhode Island. NASA-funded researchers using computer models and climate data now understand why Africa's freshwater Lake Chad has been disappearing over the last 30 years.
"Animals Regulate Their Numbers By Own Population Density"
Zoologists from the University of Toronto have cracked the ecological puzzle of how animals - in this case the arctic ground squirrel - manage to control their own population in the northern boreal forest of Canada. (Science Daily--12-07-2000)
"Antarctic Sea Urchin Shows Amazing Energy-Efficiency In Nature's Deep Freeze"
Brrrr! How well do you think you would grow if you lived in a freezer? Adam Marsh, a marine biochemist at the University of Delaware, and colleagues Rob Maxson and Donal Manahan from the University of Southern California, have discovered an important reason why the pincushion-like Antarctic sea urchin (Sterechinus neumayeri) can function so well in the polar seas surrounding the Earthís frozen continent.
"Chemical May Deter Starfish From Devouring Endangered Coral Reefs"
Researchers have discovered a chemical in sea urchins that might be used to lure starfish away from coral reefs, an endangered ecosystem they are devouring at an alarming rate. The finding was presented here today during the 2000 International Chemical Congress of Pacific Basin Societies. (Science Daily--12-18-2000)
"Computer Model To Predict Toxic Algal Outbreaks"
Blooms of blue-green algae in Australia's largest river, the Murray could be predicted up to four weeks before they occur thanks to a new computer model being developed at Adelaide University with the help of industry. (Science Daily--06-06-00)
"Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama"
Finding two fossil mollusks in a California collection led a researcher funded by the National Science Foundation (NSF) to undertake field work in Alaska that he says links the formation of the Isthmus of Panama approximately 3.6 million years ago to a reversal of water flow through the Bering Strait. (Science Daily--06-12-00)
"Increasing Carbon Dioxide Threatens Corall Reefs"
Researchers at Columbia University's Biosphere 2 Center have determined that increasing levels of carbon dioxide in the Earth's atmosphere may cause more harm to marine coral reef communities than previous research had indicated. Dr. Christopher Langdon of Columbia's Lamont Doherty Earth Observatory and his research team believe that coral growth could be reduced by as much as 40 percent from pre-industrial levels over the next 65 years. (Science Daily--05-05-00)
"Put A Pedigree Prawn On The Barbie"
Seafood lovers will soon be able to chuck a pedigree prawn on the barbie thanks to a new project by Australian scientists that will give Australia the most well-bred prawns in the world.
"Researchers Trace Toxins From Algal Blooms Through The Marine Food Web In Monterey Bay"
Researchers studying a bloom of toxic algae in Monterey Bay last summer found the algal toxin domoic acid in anchovies, sardines, and krill, all key species in the marine food web. Harvesting of anchovies and sardines for human consumption was halted and there were no reports of adverse effects on wildlife from this particular bloom. Nevertheless, the findings raise concerns about the potential effects of the toxin on a wide range of marine mammals and birds, said Mary Silver, a professor of ocean sciences at the University of California, Santa Cruz.
"Satellite Spots Unique Ocean Eddy And A Bounty Of Food For Fish"
Scientists using satellite data discovered an unusual long-lasting, whirlpool-like ocean eddy that generated a dramatic increase in the marine food supply off the Hawaiian coast in 1999.
"A Seafood Paradox: Will Fish Farming Save Or Deplete Our Ocean Fisheries?"
The world is dependent on fish farms. In fact, one out of every four fish consumed worldwide was raised on a farm. But the irony is that fish farming, or aquaculture, while helping to feed a growing human population often comes at a surprising cost to wild fish populations.
"Zebrafish Could Become Genetics 'Lab Rat' Of Choice"
In the post-genomic world, the lowly zebrafish may be king.
Scientists at Purdue University have developed a technique that allows zebrafish to pass genetic modifications to its offspring. The discovery will lead to researchers being able to study genes and proteins in a less expensive way.

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Science News
Science News is an award-winning weekly newsmagazine covering the most important research in all fields of science. Its 16 pages are packed with short, accurate articles that appeal to both general readers and scientists. Published since 1922, the magazine now reaches about 200,000 subscribers and 1.2 million readers.
Not all articles are available to the general public. Those that are not are marked with "$$", and may be accessed by those who have a subscription and register online to recieve a username and password.

"20/20 lenses coat body of sea creature"
Look closely enough at the arms of the brittlestar, a starfish relative, and you'd see that those arms are looking right back at you. Each one is coated with perfect lenses that focus light onto a nerve bundle, researchers report in the Aug. 23 Nature. Made of skeletal material, these lens structures rival recent engineering advances in microlens arrays. (Science News--8-25-2001)
$$"Bacteria cause plague in coral reef"$$
Just in time for the underwater version of flu season, researchers have identified the bacterium responsible for an unusually virulent coral disease. (Science News--04-11-98)
"Beetle Fights Bass in Moouthwash Duel"
A whirligig beetle seeps white goo when pestered, and that slow oozeóinstead of a big squirtógives the beetle a chance in a life-or-death contest inside a fish's mouth, say Cornell University researchers. (Science News--10-07-2000)
"Can This Swamp Be Saved?"
In 1905, Florida elected Governor Napoleon Bonaparte Broward, who campaigned on a promise to drain the Everglades. He didn't, but over the next century, others almost did.
Dams, canals, and levees have carved up most of the Everglades, which once covered almost 9 million acres. Everglades National Park protects only about a sixth of the historic Everglades area. Much of the rest has been planted with sugarcane, housing developments, and amusement parks. (Science News--04-17-99)
[link opens in new window]$$ "Catfish can track fish wakes in the dark" $$
Infrared photography has revealed that European catfish can stalk prey by tracking underwater wakes much as hunters on land follow footprints. (Science News--June 9, 2001; Vol. 159, No. 23)
$$"Coral-killing army recruits human bugs"$$
Coral reefs around the globe are plagued by black-band disease. The telltale black or red mat of bacteria that infects and kills corals is the work of a multitude of pathogens. Now, research on reefs off the Caribbean island of Cura?ao shows that the lethal legions enlist some bacteria that come from people. (Science News--11-24-01)
"Culture of the Sea"
On a November day 9 years ago, Christophe Guinet and his coworkers stood transfixed on the beach of an isolated island in the southern Indian Ocean. They watched as a killer whale and her 5-to-6-year-old female calf, cruising a short way offshore, abruptly stopped and together turned to face an elephant seal pup moving slowly in shallow water. (Science News--10-28-00)
"Downtown Fisheries?"
Advances may make fish farming a healthy prospect, even for inner cities. (Science News--05-13-00)
"European crab leaps to Pacific prominence"
Andrew Cohen made a disturbing discovery last week while poking around coastal mud flats in southwestern Washington. (Science News--06-13-98)
"Fisheries Donít Welcome This Whelk"
A little more than a year ago, Roger Mann and some colleagues were trawling for fish in the Chesapeake Bay when they hauled in something unexpected: a veined Rapa whelk (Rapana venosa). It marked the first reported U.S. siting of this Oriental native, known for its voracious predation of oysters, clams, and musselsóprecisely the shellfish that have gained Chesapeake waters national renown. (Science News--10-09-99)
"Fishy Sex"
The public has had an unusual number of sex stories to mull over of late. Scarcely a week goes by without a report of another politician's scandalous sexual foray or a gossip column piece on some star's in vitro fertilization.
But for science buffs with an appetite for bizarre sex yarns, new findings on the antics of fish may prove more satisfying. (Science News--October 21, 1995)
"How farm-fed seafood can deplete wild fisheries"
A decade ago, aquacultureís visionaries were touting fish farming as a way to decrease the pressure that human consumption was placing on wild fisheries. And where the farmed fish are plant eaters, this has generally proved valid, observe Rosamond L. Naylor of Stanford Universityís Institute for International Studies and her colleagues in the Oct. 30 Science. Unfortunately, they note, for carnivorous fish such as shrimp and salmon, "the opposite may be true." (Science News--11-07-98)
"An illuminating partnership for squid"
The squid Euprymna scolopes, a denizen of the shallow waters surrounding the Hawaiian archipelago, provides a shining example--literally--of symbiosis in action. The cephalopod's symbiotic partners are the bioluminescent bacteria Vibrio fischeri. (Science News--09-14-96)
"Invading Gobies Conquer Great Lakes"
In April 1990, David J. Jude found a round goby in the St. Clair River outside Detroit. A biologist at the University of Michigan in Ann Arbor, he immediately recognized the threat of invasion signaled by the North American debut of this European fish. Almost immediately, as he had feared, the goby began nesting in the adjoining Lakes Huron and Erie. Last week, Canadian officials announced that the fish has reached Lake Ontario. (Science News--07-31-99)
"Lamprey cyborg sees the light and responds"
The $6-million eel it ain't. But researchers who have taken the unprecedented step of connecting a brain, in this case a sea lamprey's brain, to a small mobile robot say they've got a roving fishbot that may someday lead to better prosthetic devices for humans. (Science News--11-11-00)
"Macho Waters--Some river pollution spawns body-altering steroids"
On the way back from a field trip to one of Alabama's barrier islands in the late 1970s, W. Mike Howell and the students in his vertebrate biology class detoured over the state line into Florida to collect some fish. (Science News--01-06-01)
$$"Marine plankton put nitrogen in a fix"$$
New genetic analyses of tropical marine microorganisms have revealed that some species of single-celled plankton are converting significant amounts of nitrogen from the air into nutrients, helping to fortify the base of the ocean's food pyramid. (Science News--08-11-01)
"Massive Fishery Resurfaces in Amazon"
An aerial view of part of Bolivia's Amazon features a curious network of zigzag and straight lines cutting across floodplains. A close-up view reveals the lines to be the remains of an earthworks project that includes a fishery operated by native peoples of the Baures region before Spanish conquest, a new study finds. (Science News--11-11-00)
"Myriad Monsters Confirmed in Water Droplets"
LONDON, November 1677óA Dutch merchant's startling claim that thousands of tiny monsters frolic within a single droplet of water was verified at the Nov. 15 meeting of the Royal Society of London. (Science News--12-18-99)
"New Flea Imperils Fish, Fouls Gear"
The Great Lakes have some new inhabitants. Nestling side by side, 50 to 80 of them could fit within 1 square inch of space. But their small size belies the potential that these fishhook water fleas hold for causing big damage. (Science News--11-13-99)
"Octopus suckers glow in the deep, dark sea"
A red octopus that drifts through deep waters off the eastern United States shines in a novel way: Its suckers flash on and off. (Science News--03-13-99)
$$"River dolphins can whistle, too, sort of"$$
In the most elaborate attempt so far to eavesdrop on Brazil's pink river dolphins, researchers have detected what may be a counterpart to seafaring dolphins' whistles. (Science News--08-11-01)
"Rogue Algae"
The Mediterranean floor is being carpeted with a shaggy, aggressive invader. (Science News--07-04-99)
"Salmon puzzle: Why did males turn female?"
Every year, rivers of chinookóthe Pacific's largest salmonóleave the ocean for an upstream trek into the streams of their birth. When these 4-to-6-year-olds reach home, they spawn and die. Surprisingly, a new study finds, most of the moms in one of Washington State's major spawning populations appear to have begun their lives as males. (Science News-- Week of Dec. 23 & 30, 2000; Vol. 158, No. 26 & 27)
"A first: Scientists oust a marine invader"
California scientists announce they have evicted from local waters a South African worm that had been devastating area mollusks. (Science News--09-04-99)
"Search for Animal Inventors"
Just how human is that prized human capacity for innovation? Does a creative genius really need the rumpled sweatshirt and the caffeine? Or for that matter, does he, she, or it need an opposable thumb to wrap around the coffee cup? (Science News--06-05-99)
"Second Group of Living Fossils Reported"
A second population of one of the most sought-after fish on the planet, the coelacanth, has turned up because a honeymooning reef ecologist got out of a taxi at the right moment. (Science News--09-26-98).
$$"Tube worms like it hot, but larvae not"$$
The larvae of some tube worms that attach themselves to the seafloor around hydrothermal vents can't stand the heat there. If they drift into chilly waters, however, they go into suspended animation until they find water at a temperature in between. This phenomenon, researchers say, could explain how animals of nonmobile species that depend upon the hot water and nutrients gushing from isolated vent systems can nonetheless be found at widely dispersed locations. (Science News--11-24-01).
"Ultimate Sea Weed Loose in America"
On June 12, while surveying a private lagoon in San Diego County, biologists ran across a strange, 14-inch-high mat of algae. (Science News--07-15-2000)
"Waking Up to the Dawn of Vertebrates"
Paleontologists have long regarded vertebrates as latecomers who straggled into evolutionary history after much of the initial sound and fury had fizzled. Chinese paleontologists, however, have discovered fossils of two fish that push the origin of vertebrates back to the riotous biological bash when almost all other animal groups emerged in the geologic record. (Science News--11-06-99)

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FOOD FOR THOUGHT

"Rake and Bake"
What's your idea of vacation fun? Might it be slogging through knee or waist-deep water for 45 minutes, raking the ocean floor in search of dinner? If it is -- and you appreciate really fresh seafood -- then consider visiting a "U-rake-it" clam farm. (Science News--03-15-97)
"'Sea'-soning inland fish"
Salmon harvested at sea taste quite different from those -- even of the same species -- caught while traversing freshwater runs. Indeed, most oceanic seafood possesses a slightly iodinelike flavor, typical of Gulf shrimp, that distinguishes them from freshwater fare. (Science News--03-07-97)

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Smithsonian Magazine "You Gotta Remember, Eels Are Weird"
Abstract of an article by Bruce Watson, originally published in the February 2000 issue of Smithsonian.

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Other Sources
"Ancient Fish Farm Revealed"
Helen Briggs
New details of a "lost" landscape of earthworks covering hundreds of square kilometres in the Bolivian Amazon have been revealed by scientists. (BBC News, Wednesday, 8 November, 2000.)

"Coelacanth Find Stuns Experts"
Researchers at the JLB Smith Institute of Ichthyology (JLBSI) in Grahamstown, South Africa were amazed when they recently received video material of coelacanths swimming in the waters off KwaZulu-Natal. The fact that six different coelacanths were observed, including adults and juveniles, suggests that a viable population of the "fossil fish" is residing and reproducing in this area.
"Male pregnancy: seahorse style!"
Jim Morel
Think about this for a moment. In the animal kingdom it is mostly the male that competes against other males for a female partner. For example, many male birds have bright colours and fancy plumage to attract a female partner. Males in some other groups have large tusks or horns to show strength and their ability to protect the female and her young.
(February, 2003, Science in Africa, Science magazine for Africa CC.)
"Pollination by flies, bees, and beetles of Nuphar ozarkana and N. advena (Nymphaeaceae)"
Barbara Lippok, Angela A. Gardine, Paula S. Williamson and S. S. Renner
Nuphar comprises 13 species of aquatic perennials distributed in the temperate Northern Hemisphere. The European species N. lutea and N. pumila in Norway, the Netherlands, and Germany are pollinated by bees and flies, including apparent Nuphar specialists. This contrasts with reports of predominant beetle pollination in American N. advena and N. polysepala. We studied pollination in N. ozarkana in Missouri and N. advena in Texas to assess whether (1) there is evidence of pollinator shifts associated with floral-morphological differences between Old World and New World species as hypothesized by Padgett, Les, and Crow (American Journal of Botany 86: 1316ñ1324. 1999) and (2) whether beetle pollination characterizes American species of Nuphar. Ninety-seven and 67% of flower visits in the two species were by sweat bees, especially Lasioglossum (Evylaeus) nelumbonis. Syrphid fly species visiting both species were Paragus sp., Chalcosyrphus metallicus, and Toxomerus geminatus. The long-horned leaf beetle Donacia piscatrix was common on leaves and stems of N. ozarkana but rarely visited flowers. Fifteen percent of visits to N. advena flowers were by D. piscatrix and D. texana. The beetles' role as pollinators was investigated experimentally by placing floating mesh cages that excluded flies and bees over N. advena buds about to open and adding beetles. Beetles visited 40% of the flowers in cages, and flowers that received visits had 69% seed set, likely due to beetle-mediated geitonogamy of 1st-d flowers. Experimentally outcrossed 1st-d flowers had 62% seed set, and open-pollinated flowers 76%; 2nd-d selfed or outcrossed flowers had low seed sets (9 and 12%, respectively). Flowers are strongly protogynous and do not self spontaneously. Flowers shielded from pollinators set no seeds. A comparison of pollinator spectra in the two Old World and three New World Nuphar species studied so far suggests that the relative contribution of flies, bees, and beetles to pollen transfer in any one population depends more on these insects' relative abundances (and in the case of Donacia, presence) and alternative food sources than on stamen length differences between Old World and New World pond-lilies.
"Robofish Act Like Reel Thing"
Bringing a dog to work is pass? in Silicon Valley, where yapping mutts have been replaced by things that don't pee on the carpet or aggravate co-workers' allergies -- desktop aquariums.
(WIRED News--April 30, 2001)
"Rulers of the Jurassic Seas"
Fish-shaped reptiles called ichthyosaurs reigned over the oceans for as long as dinosaurs roamed the land, but only recently have paleontologists discovered why these creatures were so successful. (Scientific American--December, 2000.)
"Salmon and the Northwest"
There is not much of it left. Of untouched salmon habitat there is almost none. Although salmon once occupied almost every ocean-seeking stream in the Pacific Northwest, the map where salmon go has been shrinking for the last hundred years, sometimes gradually as human forces slowly worsened the habitat, sometimes suddenly when millions of acres of habitat were blocked by dams. Open Spaces Quarterly.
"Seed output and the seed bank in Vallisneria americana (Hydrocharitaceae)
C Lokker, L Lovett-Doust and J Lovett-Doust
Seed banks and sexual reproduction are known to be significant in colonization and re-establishment of some aquatic macrophyte communities. For highly clonal aquatic macrophytes, however, there is a lack of information on seed production and seed fate as compared with annual sexual species. The seed bank for three populations of Vallisneria americana in the Huron-Erie corridor of the Great Lakes was sampled and quantified in the spring of 1994, and related to seed production in the previous season at these sites. Seed deposition rates during 1994 were also assessed. Sites varied in the proportion of plants flowering and in their tertiary sex ratios, but did not differ in seed numbers produced per unit area. The size of the seed bank was not significantly related to the previous season's seed output, and estimates of seed deposition in the following year tended to be approximately tenfold greater than seed densities found in the seed bank. The stages between seed production and subsequent seed germination are generally very dynamic, with dispersal, mortality, and predation as likely regulating factors. The potential for seedling establishment in V. americana needs to be assessed more fully before the role of seeds in population processes can be determined.
"Watch Out Water-hyacinth! New Jungle Enemies Are Coming"
You can't get to Iquitos, Peru, without a boat or a plane. But this jungle-locked city of 350,000 in the rainforests of the upper Amazon River is the business and tourism hub of Peru's eastern lowlands. (published in the March 2000 issue of Agricultural Research magazine.)

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