James P. Barry

Trophic Ecology of the Dominant Fishes in Elkhorn Slough, California, 1974-1980

Food habits of the dominant fishes collected from 1974 to 1980 at eight locations in Elkhorn Slough, California, and the adjacent ocean were investigated. Epifaunal crustacea was the major prey group identified from stomach contents of more than 2,000 fishes, followed by epifaunal and infaunal worms, and molluscs. Overall, 18 fish species consumed 263 different prey taxa, ranging from 10 taxa to 125 taxa per fish species and including 99 crustacean, 56 polychaete, and 39 molluscan taxa. Mean prey richness was greatest at stations near the ocean and lowest at inshore stations. Detailed dietary data for all prey taxa were summarized as trophic spectra for each fish species. Trophic spectra represented functional groups of prey and were used for comparisons of dietary similarity. Cluster analyses, based on trophic spectra, resulted in four feeding guilds of fishes. Of 18 fish species, seven (Amphistichus argenteus, Leptocottus armatus, Embiotoca jacksoni, Clevelandia ios, Gillichthys mirabilis, Cymatogaster aggregata, andCitharichthys stimaeus) fed principally on epifaunal crustacea. Four species (Pleuronectes vetulus, Platichthys stellatus, Phanerodon furcatus, andMyliobatus californica) consumed mostly molluscs and infaunal worms. Two species (Psettichthys melanostictus andTriakis semifasciata) fed on mobile crustacea, and five species (Hyperprosopon anale, Engraulis mordax, Clupea pallasi, Atherinopsis californiensis, andAtherinops affinis) fed largely on zooplankton and plant material. Our results suggest that high food availability enhances the nursery function of imshore habitats, and emphasize the importance of invertebrate prey populations and the indirect linkage of plant production to the ichthyofaunal assemblarly marine immigrant species that are likely ‘estuarine dependent’.

Temporal and spatial patterns in abundance and diversity of fish assemblages in Elkhorn Slough, California

Assemblages of ichthyofauna of shallow inshore habitats along Californía’s central coast are described in terms of species composition, abundance, and life-style categories. A total of 22,334 fishes from 65 species and 27 families was collected with otter trawls at six sites in the main channel and tidal creeks of Elkhorn Slough, a tidal embayment and seasonal estuary, and two nearshore ocean stations in Monterey Bay during 44 months between August 1974 and June 1980. Greater than 90% of the catch comprised 10 species. The four dominant species,Cymatogaster aggregata, Leptocottus armatus, Phanerodon furcatus, andEmbiotoca jacksoni, occurred during most or all seasons and were classified as residents or partial residents. Several abundant species were marine immigrants that seasonally use the slough as spawning and nursery grounds; this resulted in higher abundance and species richness during summer. Species collected during winter largely were slough residents. Species compsosition and richness varied with distance from the slough entrance. The ocean assemblage was most different, and its similarity to other stations decreased progressively with distance inland and into the tidal creeks. During our study, 5,074 fishes were collected by beach seine in Bennett Slough, a remote shallow marsh basin adjacent to the entrance of Elkhorn Slough. Species richness was relatively low and three euryhaline species accounted for >80% of the total catch. The species assemblage was most similar to those at the tidal creek and most shallow stations of Elkhorn Slough. Resident species numerically dominated assemblages in Bennett Slough and the most inland areas of Elkhorn Slough. The high relative abundance of marine-related fishes (classified as marine, marine immigrant, and partial resident), entering Elkhorn Slough early in life or as spawning adults indicates the importance of this habitat to nearshore fish assemblages.

Loss of genes related to Nucleotide Excision Repair (NER) and implications for reductive genome evolution in symbionts of deep-sea vesicomyid clams.

[This corrects the article DOI: 10.1371/journal.pone.0171274.].

Juvenile Mussel and Abalone Predation by the Lined Shore Crab Pachygrapsus crassipes

ABSTRACT Major rocky intertidal predators in the northeast Pacific such as sea stars, whelks, and birds can consume foundation species such as mussels and thereby affect zonation patterns and diversity in these habitats. Predation specifically on juvenile intertidal invertebrates can also substantially impact population dynamics and influence community structure. The lined shore crab Pachygrapsus crassipes (Randall, 1840) is an abundant denizen of sheltered and exposed intertidal habitats in the northeast Pacific from Canada to Mexico. This study examined potential P. crassipes predation on juvenile mussels (Mytilus galloprovincialis), whelks [Nucella ostrina (Gould, 1852)], and abalone [Haliotis rufescens (Swainson, 1822)] due to conflicting reports on the diet of this species. Crabs consumed more juvenile mussels and abalone than seaweed (Ulva lactuca) and fed preferentially on the smallest mussels (6- to 10-mm size class). Further experiments showed that predation on mussels by P. crassipes was highly size dependent, with the largest crabs consuming over twenty-five 15-mm mussels per day. Field outplant experiments revealed that P. crassipes consumed high numbers of juvenile mussels in a natural setting, meaning that it could substantially affect mussel recruitment. This crab species appears to be an opportunistic predator that could have significant impacts on the recruitment and early life history of several invertebrate prey species.