Juvenile sockeye salmon (Oncorhynchus nerka) in Lake Washington experience very high growth rates, but the mechanisms regulating their growth rates are poorly understood. The potential for food quality limitation of growth was tested using a coupled bioenergetics and mass balance model. Sockeye and zooplankton prey species were analyzed for their fatty acid composition. Ratios of phosphorus to ...

Thoracopod developmenl was analyzed for 25 species from 18 genera among the Cyclopidae. One species from each of 7 genera of presumed older cyclopoids. 5 poeciloslomaloid genera. 3 harpacticoid genera, 5 calanoid genera, and a siphonoslomatoid were studied to help establish ancestral patterns of thoracopod development. Ancestral character states were inferred from the presence of identical stat...

The transparency-gradient hypothesis argues that ultraviolet radiation (UV) is a primary determinant of the vertical distribution of zooplankton in transparent lakes with fewer fish, while fish predation is the primary driver in less transparent lakes where fish are more abundant. We measured vertical profiles of UV, photosynthetically active radiation (PAR, essentially visible light used as a ...

In this modern age of genomics, it is easy to forget that Mother Nature keeps many surprises for us up her sleeve; hubris is only human, after all. A paper in this issue, describing “The peculiar epidemiology of dracunculiasis in Chad,” provides an example. For more than 20 years now, a dedicated battalion of public health workers has been engaged in the international struggle to eradicate Guin...

In this study, the structure and ultrastructure of the digestive system are compared in the early larval stages (nauplii I and II) of two copepod calanoid species, Acartia clausi Giesbrecht, 1889 and Hemidiaptomus roubaui Richard, 1888. The nauplii I of both species have no functional digestive tract, which is represented initially only by a blind esophageal slit and yolky endodermal cells, whi...

A study of pelagic and littoral species richness among microcrustaceans in 2,466 Norwegian lakes recorded 120 crustacean species: 77 cladocerans, 31 cyclopoids, and 12 calanoids, respectively. Very few species were strictly pelagic, and the pelagic crustacean zooplankton species were by far outnumbered by their littoral counterparts. More than two-thirds of the total crustacean species numbers ...