Air-exposure behavior: a restricted or a common conduct among intertidal hermit crabs?

A new behavior related to shell care was recently reported for the intertidal hermit crab Clibanarius erythropus (Latreille, 1818) in the Gulf of Cádiz (southwestern Europe). It also has been observed in other species of the diogenid genera Clibanarius Dana, 1952, and Calcinus Dana, 1951, however, it has not been described as an active behavior. In the present study, intertidal hermit crabs from different species and localities were sampled to assess if air-exposure is a shell cleaning behavior restricted to some species of intertidal hermit crabs or if it is a more generalized behavior among species inhabiting intertidal habitats. The results revealed that air-exposure is an active behavior in species of Clibanarius and Calcinus, since we observed it also in Clibanarius albidigitus Nobili, 1901, and Calcinus obscurus Stimpson, 1859, from the Pacific coast of Costa Rica, although not in other intertidal species studied by us. We found interspecific differences in tolerance to physical stress of emerged hermit crabs. This air-exposure tolerance can be interpreted as a physiological adaptation to desiccation stress and is also related to the shell type they inhabit. Also, we provide additional features and details of the air-exposure behavior, combining observations of the first description in 2015 with our new field observations.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Biology and fishery of the arched box crab Calappa convexa de Saussure (Crustacea, Brachyura, Calappidae) In the Southeastern Gulf of California, Mexico

The arched box crab (Calappa convexa) is commonly caught in gillnets as by-catch of the spiny lobster (Panulirus spp.) fishery in southern Sinaloa, Mexico, a locally exploited fishing resource. Crabs were sampled monthly from May 1998 to April 1999 and a total of 274 specimens (132 males and 142 females) were captured. The distribution of the resource was homogeneous (present in 72% of the samples) throughout the sampling area. The overall sex ratio (female:male) was 1:0.92 (χ2 > 0.05). The capture per unit effort (CPUE) varied from 0.81 g/100m2/h to 9.10 g/100m2/h. Maximum catch was obtained in June while minimum catches occurred in December and March. The CPUE values differed significantly (ANOVA P 75 mm CL), females were narrower while the opposite occurred in males. Left and right chelae reached a combined fresh weight of 100 g, in males of about 75.0 mm CL, while in females this weight was reached at 79.0 mm CL

A new species of the hermit crab genus <i>Areopaguristes</i> Rahayu & McLaughlin (Crustacea, Decapoda, Anomura, Paguroidea, Diogenidae) from the Mexican Pacific

A new species of hermit crab, Areopaguristes espetacioni, family Diogenidae, is described and illustrated in detail, including the color pattern in live/fresh specimens. This is the fifth species of Areopaguristes reported from the eastern Pacific. Given the morphological similarity between Areopaguristes espetacioni n. sp. and A. tudgei Lemaitre & Felder, 2012, these can be considered sister species. The presence of a long rostrum, the antennal flagella with short setae, chelipeds and ambulatories legs with dense plumose setae, and telson with calcareous teeth on the posterior margin allow to separate Areopaguristes espetacioni n. sp. from all other species in the genus previously described for the region. A key for Areopaguristes species from the eastern tropical Pacific is provided

In situ observations on the habitat and abundance of the squat lobster <i>Gastroptychus perarmatus</i> (Haig, 1968) (Crustacea: Decapoda: Chirostylidae) in the n orthern Gulf of California, Mexico

Living specimens of Gastroptychus perarmatus (Haig, 1968), a chirostylid squat lobster, were observed on colonies of gorgonian corals and sponges in the northern Gulf of California. Video footage and photographs obtained from the Remotely Operated Vehicle JASON dive north of Angel de La Guarda Island in the northern Gulf of California indicate that this squat lobster lives on coral specimens of Callogorgia, probably C. flabellum (Ehrenberg, 1834), and on one or two unidentified species of sponge(s). Seven sites were observed to contain G. perarmatus with the number of individuals per host varying from 2 to 11. No specimens were observed on the sea floor away from a host. Review of videos indicates that most individuals of G. perarmatus observed remained motionless in the same position throughout the video recording period (max. 30 seconds), with the body erect and the chelipeds extended, presumably to facilitate collection of organic particles transported by the current. At one site, however, the video shows one adult specimen grasping large particles of floating debris retained on the gorgonian. Until recently there were no records of G. perarmatus since it was described from California in depths of 229m (north of Anacapa Island). A few specimens were accidentally captured in a benthic sledge in the northern Gulf of California in 2011. This is a new record for the area, including a new maximum depth record (705-710 m) for the species. This rare species of squat lobster and its host the gorgonian coral would be subject to severe environmental impacts if fishing or mining activities were developed in the area

Caprella suprapiscis sp. nov. (Crustacea: Amphipoda: Caprellidae) from the Pacific coast of Mexico

Galván-Villa, Cristian M., Ayón-Parente, Manuel (2015): Caprella suprapiscis sp. nov. (Crustacea: Amphipoda: Caprellidae) from the Pacific coast of Mexico. Zootaxa 3956 (4): 569-578, DOI: http://dx.doi.org/10.11646/zootaxa.3956.4.

FIGURE 2 in New records of the deep-sea anemone Phelliactis callicyclus Riemann-Zurneck, 1973 (Cnidaria, Actiniaria, Hormathiidae) from the Gulf of California, Mexico

FIGURE 2. Photographs of Phelliactis callicyclus Riemann-Zurneck, 1973. A) From the MIR submarines dives in the Guaymas Basin (from Sanamyan & Sanamyan 2007). B–F) From the JASON ROV dives at different dive locations, May 2008 cruise; note the two specimens in figure D