Use of principal components analysis to describe the snail shell resource for hermit crabs

Principal components analysis of morphometric data from snail shells occupied by hermit crabs enables the important dimensions of the shell to be described and quantified. A high correlation of the first principal component with crab size shows this component to be a better estimator of overall shell size than any of the original morphometric variates. Principal component II separated the shells utilized by adjacent populations of Coenobita and Calcinus according to shape.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21794/1/0000192.pd

Parasitic copepods (Crustacea, Hexanauplia) on fishes from the lagoon flats of Palmyra Atoll, Central Pacific

We surveyed copepods parasitic on the fishes at Palmyra, a remote atoll in the Central Indo-Pacific faunal region. In total, we collected 849 individual fish, representing 44 species, from the intertidal lagoon flats at Palmyra and recovered 17 parasitic copepod species. The parasitic copepods were: Orbitacolax williamsi on Mulloidichthys flavolineatus; Anuretes serratus on Acanthurus xanthopterus; Caligus confusus on Carangoides ferdau, Carangoides orthogrammus, Caranx ignobilis, Caranx melampygus, and Caranx papuensis; Caligus kapuhili on Chaetodon auriga and Chaetodon lunula; Caligus laticaudus on Rhinecanthus aculeatus, Pseudobalistes flavimarginatus, M. flavolineatus, Upeneus taeniopterus, Chrysiptera glauca, and Epinephalus merra; Caligus mutabilis on Lutjanus fulvus and Lutjanus monostigma; Caligus randalli on C. ignobilis; Caligus sp. on L. fulvus; Caritus serratus on Chanos chanos; Lepeophtheirus lewisi on A. xanthopterus; Lepeophtheirus uluus on C. ignobilis; Dissonus similis on Arothron hispidus; Nemesis sp. on Carcharhinus melanopterus; Hatschekia longiabdominalis on A. hispidus; Hatschekia bicaudata on Chaetodon auriga and Chaetodon lunula; Kroyeria longicauda on C. melanopterus and Lernanthropus sp. on Kyphosus cinerascens. All copepod species reported here have been previously reported from the Indo-Pacific but represent new geographical records for Palmyra, demonstrating large-scale parasite dispersion strategies

Ovicides paralithodis (Nemertea, Carcinonemertidae), a new species of symbiotic egg predator of the red king crab Paralithodes camtschaticus (Tilesius, 1815) (Decapoda, Anomura)

Ovicides paralithodis sp. n. is described from the egg mass of the red king crab Paralithodes camtschaticus (Tilesius, 1815) from the Sea of Okhotsk, off Hokkaido, Japan, and Alaska, USA. Among four congeners, O. paralithodis can be distinguished from O. julieae Shields, 2001 and O. davidi Shields and Segonzac, 2007 by having no eyes; from O. jonesi Shields and Segonzac, 2007 by the presence of basophilic, vacuolated glandular lobes in the precerebral region; and from O. jasoni Shields and Segonzac, 2007 by the arrangement of the acidophilic submuscular glands, which are not arranged in a row. Ovicides paralithodis represents the third described species of egg-predatory nemertean from P. camtschaticus, the second described carcinonemertid species from Japan, and the 21st described species in the family. The intensity of infestations may exceed 24,000 worms per a single egg-bearing pleopod of P. camtschaticus. A preliminary molecular phylogenetic analysis based on sequences of 28S rRNA and cytochrome c oxidase subunit I genes among selected monostiliferous hoplonemertean species supported the monophyly of Carcinonemertidae, suggesting that within the lineage of the family, evolution of the unique vas deferens, Takakura's duct, preceded loss of accessory stylets and accessory-stylet pouches