There is a greater quantity and diversity of lipophilic secondary metabolites produced by seaweeds within tropical relative to temperate regions. Coevolutionary arms-race theory predicts that tropical herbivores should more readily tolerate consuming chemically-rich seaweeds than do temperate herbivores, however, tests of this prediction are rare. We assessed the willingness to consume freeze-d...

This study investigates predation by the vent zoarcid fish Thermarces cerberus through gastrointestinal analyses of 27 specimens collected with the submersible ALVIN at vents at 91500N on the East Pacific Rise. T. cerberus fed most frequently on gastropod mollusks (mainly Lepetodrilus elevatus) and amphipod crustaceans (mainly Ventiella sulfuris). Species found occasionally in high abundance in...

This study investigated the uptake and effects of a common human pharmaceutical, propranolol, on the structure and function of a coastal Baltic Sea model community consisting of macroalga (Ceramium tenuicorne), mussels (Mytilus edulis trossulus), amphipods (Gammarus spp.), water and sediment. The most sensitive species, the mussel, was affected to the same extent as in previous single species s...

High levels of atmospheric carbon dioxide are driving the acidification of the world’s oceans, with considerable and generally negative impacts on the physiology, performance and survival of marine organisms. The differential and often idiosyncratic responses shown by different taxa suggest that interspecific interactions may be drastically affected by ocean acidification. Here, we quantified t...

Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or chemical properties of the tunic. One of such is chemical defense based on secondary metabolites. We analyzed a series of colonial Antarctic ascidians from deep-water collections belonging to the genera Aplidium and Synoicum to evaluate the incidence of organic deterrents and their variability. The...

A number of parasites with complex life cycles can abbreviate their life cycles to increase the likelihood of reproducing. For example, some trematodes can facultatively skip the definitive host and produce viable eggs while still inside their intermediate host. The resulting shorter life cycle is clearly advantageous when transmission probabilities to the definitive hosts are low. Coitocaecum ...

Understanding the individual and interactive roles of consumer species is more than academic when the host plant is a subject of intense conservation interest. In a mesocosm experiment, we compared effects of common invertebrate grazers in San Francisco Bay seagrass (Zostera marina, eelgrass) beds, finding that some species (a native opisthobranch, Phyllaplysia taylori; a native isopod, Idotea ...

The potential ecological impacts of anaerobic degradation of vegetable oil on freshwater sediments were investigated. Sediment toxicity was evaluated using two regulatory biotests: the Microtox Solid Phase Test and an amphipod (Hyalella azteca) bioassay. The results of the Microtox test showed that the toxicity of the vegetable-oil-contaminated sediments (about 17–33 g oil/kg dry sediments) inc...

Intersexuality occurs in a diverse range of animals, and its study offers insights into basic reproductive biology. Investigations in amphipods suggest intersexuality results from incomplete feminisation caused by sex-distorting parasites. It has also been noted that 2 intersex phenotypes occur in males of the amphipod Echinogammarus marinus, an external phenotype, in which males possess rudime...

Numerous molecular studies have identified morphologically cryptic, freshwater invertebrate species, but have not suggested possible mechanisms for their phenotypic stasis. The amphipod crustacean genus Hyalella contains numerous morphologically cryptic species in the H. azteca complex, as well as a small number of morphologically very divergent, narrowly endemic taxa. One such taxon, Hyalella ...