Crustacea,

Added t.-p. in English; text in Norwegian and English.

Effects of destratification and aeration of a lake on the distribution of planktonic crustacea, yellow perch and trout /

Includes bibliographical references (p. 22).

An annotated checklist of Hawaiian barnacles (class Crustacea, subclass Cirripedia) with notes on their nomenclature, habitats, and Hawaiian localities, /

Mode of access: Internet.

On the supposed existence of Metamorphoses in the Crustacea.

Received May 25,-Read June 18, 1835.

An account of the Crustacea of Norway, with short descriptions and figures of all the species.

Mode of access: Internet.

Guide to the Crustacea, Arachnida, Onychophora and Myriopoda : exhibited in the Department of zoology, British museum (Natural history) ... With 90 illustrations.

"The section on the Crustacea is written by Dr. W. T. Calman, that on the Arachnida and Myriopoda by Mr. A. S. Hirst, and the portions dealing respectively with the Onychophora and with the Pestastomida ... by Mr. F. Jeffrey Bell." - Pref.

Feeding ecology of the fish ectoparasite Gnathia sp. (Crustacea: Isopoda) from the Great Barrier Reef, and its implications for fish cleaning behaviour

The feeding rate of a parasitic gnathiid isopod on fish was examined. Individual fish, Hemigymnus melapterus, were exposed to gnathiid larvae and sampled after 5, 10, 30, 60, and 240 min. I recorded whether larvae had an engorged gut, an engorged gut containing red material, or had dropped off the fish after having completed engorgement; variation among sampling times and larval stages was analyzed using generalized linear mixed model analyses. The likelihood that larvae had an engorged gut increased with time and varied with larval stage. First stage (1.45 mm) larvae. After 30 min, however, most (>93%) larvae had an engorged gut regardless of their larval stage. The likelihood of red material in the gut of third stage larvae increased over time (46% after 30 min, 70% after 60 min, and 86% after 240 min) while that of first and second stage larvae remained relatively low (

Cannibalism in juvenile blue-swimmer crabs Portunus pelagicus (Linnaeus, 1766): effects of body size, moult stage and refuge availability

Factors influencing the rate of cannibalism in juvenile blue-swimmer crabs Portunus pelagicus were investigated under controlled conditions using time-lapse video recordings. This study was undertaken to improve blue-swimmer crab culture and experimentally addressed (1) prey vulnerability (2) cannibal-victim interactions, and (3) activity patterns of juveniles in varying degrees of refuge. Crabs used in the study were aged 15 weeks and sorted into two size classes; small (less than or equal to 60 mm carapace width (CW)) and large (greater than or equal to65 mm CW) of a similar sex ratio. Vulnerability and thus survival was influenced by body size variation, moult stage and refuge availability. Crabs with carapace width less than or equal to 60 mm were more vulnerable than larger individuals, as indicated by significant differences in survival rates. As predicted, juveniles in transition stages associated with ecdysis were especially vulnerable. Premoult (redliner) crabs appeared to be in a high state of agitation as evidenced by the frequency of agonistic encounters and this may be a contributing factor to the high mortality observed at this critical premoult stag. increases in refuge density increased survival of juveniles proportionally, indicating that the quantity of shelter is important for reducing cannibalism in this species. Cannibal-victim interactions were frequently asymmetrical in terms of size and moult stage. Cannibals were significantly heavier than victims, and were predominantly at intermoult stage. Sexual biases among cannibals and victims were not found in this study. Activity patterns of juveniles were influenced by the experimental conditions. Crabs provided with high refuge showed reduced aggressive activity and increased time spent resting, but unchanged locomotion or feeding activity. Regular grading as well as the presence of suitable shelter for newly moulted crabs is recommended for improving culture of P. pelagicus. Research into inducing synchronous moulting may also yield promising results. (C) 2004 Elsevier B.V. All rights reserved.

American Alligator Digestion Rate of Blue Crabs and Its Implications for Stomach Contents Analysis

Stomach contents analysis (SCA) provides a snap-shot observation of a consumer's diet. Interpretation of SCA data can be complicated by many factors, including variation in gastric residence times and digestion rates among prey taxa. Although some SCA methods are reported to efficiently remove all stomach contents, the effectiveness of these techniques has rarely been tested for large irregular shaped prey with hard exoskeletons. We used a controlled feeding trial to estimate gastric residency time and decomposition rate of a large crustacean prey item, the Blue Crab (Callinectes sapidus), which is consumed by American Alligators (Alligator mississippiensis), an abundant apex predator in coastal habitats of the southeastern United States. The decomposition rate of C. sapidus in the stomachs of A. mississippiensis followed a predictable pattern, and some crab pieces remained in stomachs for at least 14 days. We also found that certain portions of C. sapidus were prone to becoming caught within the stomach or esophagus, meaning not all crab parts are consistently recovered using gastric lavage techniques. However, because the state of decomposition of crabs was predictable, it is possible to estimate time since consumption for crabs recovered from wild alligators. This information, coupled with a detailed understanding of crab distributions and alligator movement tactics could help elucidate patterns of cross-ecosystem foraging by the American Alligator in coastal habitats.

A comprehensive and integrative reconstruction of evolutionary history for Anomura (Crustacea: Decapoda)

Background The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history—phylogeny, divergence times, character evolution and diversification—of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest anomuran phylogeny to date. The anomuran fossil record allowed us to incorporate 31 fossils for divergence time analyses. Results Our best phylogenetic hypothesis (morphological + molecular data) supports most anomuran superfamilies and families as monophyletic. However, three families and eleven genera are recovered as para- and polyphyletic. Divergence time analysis dates the origin of Anomura to the Late Permian ~259 (224–296) MYA with many of the present day families radiating during the Jurassic and Early Cretaceous. Ancestral state reconstruction suggests that carcinization occurred independently 3 times within the group. The invasion of freshwater and terrestrial environments both occurred between the Late Cretaceous and Tertiary. Diversification analyses found the speciation rate to be low across Anomura, and we identify 2 major changes in the tempo of diversification; the most significant at the base of a clade that includes the squat-lobster family Chirostylidae. Conclusions Our findings are compared against current classifications and previous hypotheses of anomuran relationships. Many families and genera appear to be poly- or paraphyletic suggesting a need for further taxonomic revisions at these levels. A divergence time analysis provides key insights into the origins of major lineages and events and the timing of morphological (body form) and ecological (habitat) transitions. Living anomuran biodiversity is the product of 2 major changes in the tempo of diversification; our initial insights suggest that the acquisition of a crab-like form did not act as a key innovation.