A 40-day feeding experiment was conducted to investigate the effect of previous food restriction on the compensatory growth response in Chinese shrimp, Fenneropenaeus chinensis. Four groups of shrimp with initial body weight of 2.189 ± 0.093 g (mean ± SE) were used, in which the control group (Group C) received ad libitum rations throughout the experiment, and the other three groups (expressed as Group R4, R8, and R12) were first fed at 4%, 8% and 12% of body weight per day (% B.W.·day⁻¹), respectively, for 10 days and were then fed ad libitum for a recovery period of 30 days. After 10 days of restricted feeding, the shrimp showed increased body contents of moisture and ash and decreased contents of lipid, protein, and energy compared with the controls. The effect of previous food restriction on body biochemical composition gradually reversed during the period of ad libitum feeding. At last, there were no significant differences in body composition among all groups, with the exception of a higher lipid content appeared in Group R12. Specific growth rates in terms of wet weight, dry matter, protein, and energy (SGR_w, SGR_d, SGR_p, and SGR_e) decreased with decline in ration, while feed conversion efficiencies (FCE_w, FCE_d, and FCE_p) were highest at feeding level of 12% B.W.·day⁻¹ during the course of food restriction. Following transfer from restricted to ad libitum feeding regime, all the restricted groups exhibited significantly higher food intake (FI_w) and SGR_w than the control group. However, this compensation response only occurred within the first 10 days of ad libitum refeeding. During the period of ad libitum refeeding, all the restricted groups showed just slightly higher feed conversion efficiencies than that of the control group. At the end of the experiment, Group R12 was able to fully catch up with the control in body weight, while the other two restricted groups still weighed less than the control. It appears that both completely and partially compensatory growth occur in Chinese shrimp, and this growth compensation is mainly dependent on increasing food intake (hyperphagia) and possibly is contributed somewhat by improvement in feed conversion efficiency.

Palaemon serratus (Pennant, 1777) is a shrimp with a high market value. It can be extensively produced in salt marshes with good survival rates, and it takes a reasonable period (8–10 months) to attain marketable size. For these reasons, it seems to have a good aquaculture potential. However, little is known about the nutritional requirements of this species, especially at the larval stages, and this may impose constraints to its successful rearing. This paper describes the changes occurring in the fatty acid profile of four developmental stages of Palaemon serratus eggs, newly hatched Zoea I larvae, and Zoea I starved for 24 and 48 hours, with the purpose of assessing larval fatty acid requirements. We also studied the effects of eight diets composed of microalgae (Chlorella sp. and Isochrysis galbana), rotifer (Brachionus plicatilis) and non-enriched or enriched brine shrimp (Artemia franciscana) nauplii on the fatty acid profiles of P. serratus postlarvae. Analysis of the P. serratus eggs revealed a high PUFA and HUFA content, which confirms their nutritional importance. The best results, in terms of postlarval fatty acid profile, were achieved with a diet of Artemia nauplii enriched with Protein Selco®, followed by a diet of B. plicatilis, Artemia nauplii, and Isochrysis galbana. The results from the present study are compared with survival and growth data from a previous study, and it is concluded that Protein Selco® appears to be the best Artemia enrichment product for the larval rearing of P. serratus.

Most crustaceans inhabiting temporary pools have resting stages that can remain dormant for many years. Only a fraction of the resting stages hatch each time the pool floods, as a safeguard against unpredictable events resulting in complete reproductive failure. There is likely to be a selective advantage in the ability of resting stages to respond to signals indicating likely environmental conditions and to adjust their hatching fraction in response. We examine whether such an ability exists in the resting stages (diapausing eggs) of the ostracod Heterocypris incongruens, which inhabits temporary freshwater pools in northern Israel. The active stages are subject in some seasons to predation by larvae of the fire salamander (Salamandra salamandra L.). We predicted that a lower fraction of H. incongruens eggs would hatch in water in which S. salamandra larvae had been kept than in water that had not contained S. salamandra larvae. We found no such effect. We discuss possible reasons for the absence of the expected response. A lower proportion of H. incongruens eggs hatched in water with higher conductivity. This may reduce the risk of active stages being killed by desiccation before being able to complete their life cycle

Pagurus longicarpus readily removes small prey (Artemia nauplii) from suspension under laboratory conditions. In our experiments, clearance rates of recently hatched nauplii were equal for male and female crabs and for crabs within or removed from their gastropod shells. Most feeding trials were performed with shell-less crabs. Crabs fed more effectively on nauplii in water of ambient salinity (30‰) than at 15‰. Feeding was more efficient between 20° and 30°C than at lower temperatures and was equally efficient in the light or dark. Rates of nauplii consumption were positively correlated with crab length. At concentrations of 4 nauplii/ml, crabs removed approximately 40% and 60% from suspension in 5 and 10 minutes, respectively. Nauplii were cleared more rapidly at higher concentrations. First zoeae of the brachyurans Dyspanopeus sayi and Carcinus maenas were readily removed from suspension by Pagurus longicarpus, but at lower rates than the smaller Artemia nauplii. The relatively large first zoeae of Palaemonetes vulgaris also were removed from suspension; in this case the crabs used their chelipeds to capture the zoeae. Up to 35% of recently hatched veligers of the gastropod Crepidula plana, the smallest prey species, were removed in 5-minute trials. The stomachs of crabs collected in the field contained what appeared to be a benthic diet of detritus but with some evidence of crustacean fragments that could have been derived from suspension. The mouth parts of P. longicarpus are not specialized for suspension feeding as in some species of hermit crabs. The activities of these mouth parts in conjunction with movements of the chelipeds and anterior walking legs combine to produce eddy currents around the head bringing suspended prey to the vicinity of the outer mouth parts where prey are grasped and ingested. Although the potential for active and efficient suspension feeding has been demonstrated, further observations are required to evaluate its importance in the crabs' natural habitat.

Orientation of the hermit crabs Clibanarius antillensis to solid and striped targets of different visual angles was tested in a circular arena upon exposure to background sea water, calcium concentrations, gastropod odor, predatory fish odor, and seagrass odor. The test hypotheses were that (1) this hermit crab has the capacity to use visual cues for orientation and (2) it discriminates between objects on the basis of visual and chemical information. Adult crabs were tested during the day without their gastropod shells, and orientation varied with concentration and chemical cue. In general, orientation increased as concentration increased up to a maximum orientation response and then declined at higher concentrations. Solid targets representing gastropod shells attracted crabs in the presence of calcium and gastropod odor. Orientation toward striped targets representing seagrass increased in the presence of seagrass odor. Finally, orientation directly away from a target (predator avoidance response) was only observed in the presence of predator odor. Thus, both hypotheses were supported.

In Petrolisthes violaceus, the last pereiopods are reduced, chelated, and highly movable. Several aggregations of specialised grooming setae are located mainly on the carpus, propodus, and dactylus of 5th pereiopods. Under laboratory conditions, ovigerous females were frequently observed to groom brooded embryos with this appendage. Grooming of the brood mass was most often observed during the day when brooding females remained relatively immobile, while embryo grooming was almost absent during the night when brooding females were otherwise highly active. When small shell pieces, dead embryos belonging to the same species, or small epoxy resin balls were inserted into the brood mass, the 5th pereiopods did not search for, manipulate, nor actively discard them. However, foreign objects were “incidentally removed” from the brood mass due to the preening of brooded embryos by the 5th pereiopods. Females that had the 5th pereiopods experimentally removed suffered higher embryo mortality during incubation than females with intact 5th pereiopods. Thus, brood grooming by 5th pereiopods significantly enhances survival of embryos during incubation. Compared to females with intact 5th pereiopods the hatching process of experimental females was significantly longer. Active brood care behaviour as described here for P. violaceus may also occur in other Anomuran species, because most of them bear a 5th pereiopod modified as a chelated grooming structure.

Tetraclita squamosa and Tetraclita japonica have recently been separated into two species using allozyme and DNA analysis. The morphologies of the two species, however, have not been described fully, resulting in confusion over diagnostic characters and identification. Tetraclita squamosa has greenish parietes and the tergo-scutal flaps are black with two pairs of white spots. Tetraclita japonica has purplish-grey parietes and the tergo-scutal flaps are not patterned. These characters are good for in-situ species identification. The third cirrus of T. japonica possess an additional bidentate-type seta, which is absent from T. squamosa. Results of discriminant function analysis indicate the shape of the parietes and the scutum geometry of T. squamosa and T. japonica show intraspecific variation between sites, indicating they are not diagnostic characters for separating the two species. The basi-scutal angle of the tergum, however, is significantly different between the two species and is useful in distinguishing the species. By means of these specific criteria, the two species can be identified with confidence on the shore and in the laboratory.

The funnel of Gammarus oceanicus extends as a fold of the foregut wall into the midgut lumen. It comprises an anterior segment, to which both foregut epithelium and cuticle contribute, and a posterior segment that lacks the epithelium. The latter segment consists of two layers of foregut cuticle that are in close contact and extend distally beyond the point where the foregut epithelium turns back on itself; contact between the two cuticular layers develops as the epithelium retracts from between them, in postmolt. Light microscopy does not consistently distinguish between the funnel's posterior segment and the peritrophic membrane found within mid- and hindguts; however, their ultrastructural organizations are distinctly different, and an origin of peritrophic membrane from the funnel of some amphipods, as suggested in the literature, is not the case for Gammarus oceanicus. Scattered within the posterior segment cuticle are clusters of short, highly curved, electron-lucent rods. Such features have not been described from other crustacean cuticles. However, rather than being novel structures, they are interpreted as artifacts produced by sectioning of the abundant chitin macrofibrils of the cuticle.

A revision of clam shrimps of the family Limnadiidae from Venezuela resulted in eight species, of which seven belong to the genus Eulimnadia and one to Metalimnadia. Eulimnadia texana, previously reported from North America and Brazil, now has a less discontinuous distribution as does E. cylindrova, previously reported from North America and the Galapagos Islands. Collections of specimens of E. geayi and Metalimnadia serratura were made. The species E. colombiensis and E. magdalenensis, once believed to be endemic to Colombia, now have a larger distribution that includes the Venezuelan lowlands. Finally, one new limnadiid species, Eulimnadia follisimilis, is described.

A new species of Porcellidiidae, Porcellidium poorei, is described from the seagrass beds of Port Phillip Bay, Victoria, Australia. The validity of all genera of Porcellidiidae is discussed, and Murramia, Acutiramus, Kioloaria, Kensakia, and Mucrorostrum are synonymised with Porcellidium. The family diagnosis is expanded. A key to the genera is provided.

Twenty-six species of freshwater shrimps and crabs, belonging to 14 genera of four families (Atyidae, Palaemonidae, Parathelphusidae, and Grapsidae) are reported from Halmahera, Indonesia. Of them, 10 are new records for the island while one species of Macrobrachium is here described as new. Description for new species, diagnoses for poorly known species, and taxonomic discussions for all species are provided.

The species of the genus Raymunida from the Pacific and Indian oceans are revised using morphological characters and the mitochondrial cytochrome oxidase subunit I sequences. Four new species are described (R. confundens, R. dextralis, R. erythrina, and R. insulata), and the status of R. bellior and R. elegantissima are revised. The species of Raymunida can be identified by subtle morphological characters, which match differences in mitochondrial nucleotide sequences. Therefore, the sequence divergences confirm the specific and phylogenetic value of some morphological characters (e.g., length of the mesial spine on the basal antennal segment, length of the walking legs). Furthermore, they confirm the importance of the color pattern as a diagnostic character. The widespread species (R. elegantissima), known from the Philippines to Fiji, shows minimal divergence between specimens from different localities (maximum of 3 nucleotide differences or 0.2% mean divergence). The phylogenetic reconstruction agreed with the monophyletic condition of Raymunida and its differentiation with respect to the genus Munida (in which Raymunida species had previously been included) and Agononida.

The complete larval development of the land hermit crab Coenobita compressus is described from specimens reared in the laboratory at 26°C. Eighty-eight percent passed through five zoeal stages and 12% passed through four zoeal stages before metamorphosing 21–33 days after hatching. Megalopae left their water dishes as soon as seven days after metamorphosis, buried themselves in damp sand approximately 29 days after metamorphosis, and emerged as young crabs 1–5 days later. Coenobita compressus zoeae can be distinguished from the other seven described coenobitids by the setation of the maxillule and antenna, whereas the megalopa can be distinguished by the segmentation of the second and third maxillipeds. Characters are also given to distinguish C. compressus zoeae from those of sympatric marine hermit crab zoeae.

The first zoea of Lauridromia indica (Gray, 1831) is described and compared with other dromiid larvae. Forty-six characters of dromiid first zoea and megalopa larvae (seven genera and 11 species) are summarized, and their concordance with the taxonomy of recently revised genera, based on adult morphology, is tested. For the most part, larval characters support the new generic arrangement of McLay (1993). However, the larvae of Dromia wilsoni are very different from those of congeners, suggesting that it should be placed in a new genus. Almost half of the species whose larvae are known show various degrees of abbreviated development. All known dromiids with direct development occur in Australian waters. This mode of development is not confined to a monophyletic group of dromiids and seems to have evolved independently several times. The distinctiveness of the shell-carrying genera Conchoecetes and Hypoconcha is reinforced by larval characters and their similarity suggests descent from a common ancestor. On the basis of larval and adult characters, these two genera should eventually be placed in a separate new family.

Larval stages of the spider crab Goniopugettia sagamiensis (Gordon, 1931) (subfamily Epialtinae) collected from the continental shelf break are described based on laboratory-reared materials. Larval development of G. sagamiensis consists of two zoeal and one megalopal stage as typical in majid crab larvae. It took 31–35 days from hatching to the crab 1 stage at 14.1–18.5°C. The diameters of eggs of the present species are relatively large (1.04–1.24 mm), and the larvae have a mass of yolk granules throughout the larval stages. The larvae metamorphosed into the crab 1 stage without feeding. Such a lecithotrophic development as found in the present species is only known in Chlorinoides longispinus (De Haan, 1839) (subfamily Majinae) among the majid species of Japan. General morphology of the zoeal stages of G. sagamiensis is similar to C. longispinus, for example, the rudiment of the mandibular palps in the zoea 1 stage.

A new species of spider crab, Pyromaia acanthina, is described based on specimens collected during a recent sampling program along the Caribbean coast of Colombia. This new species is most similar to P. propinqua Chace, 1940, a species also collected during this study that had not been found or mentioned in the literature since its original description from Cuba. The presence of these two species on the Colombian coast represents the first record of the genus Pyromaia Stimpson, 1871 in the southern Caribbean or northeastern South America. Pyromaia propinqua is redescribed and compared with the new species. The two differ from the other congeners, P. cuspidata Stimpson, 1871, P. arachna Rathbun, 1924, and P. tuberculata (Lockington, 1877), in features of the carapace, ambulatory legs, and male first pleopods. A summary of the classification of this genus, its definition, and distribution of species is presented together with a key to their identification.

This study provides descriptive information on the natural history and life history of an invasive population of Charybdis hellerii, which is native to the Indo-West Pacific region, and which invaded the western Atlantic Ocean in the late 1980s. In this study, sampling at 27 sites along the Indian River Lagoon, Florida, during 1995–1999 showed that this crab is established in structured habitats (riprap of jetties, coralline ledges, mangrove roots, and dense algae) near inlets of the central and southern portions of the lagoon. It was not found at sites away from inlets, nor from apparently suitable structured habitats at an inlet to the north of Cape Canaveral. Although crab abundances were low, the broad size structure of the population indicates sustained recruitment into the population. Data on life history features and formal larval descriptions were derived from a cohort of larvae reared in the laboratory, including egg incubation and hatching, complete larval development, early crab instars, juvenile growth to sexual maturity, and brood production. Larval descriptions include detailed drawings of all apendages, as well as the carapaces, abdomens, and telsons for all 6 zoeal stages, and a photograph of the megalopa. Charybdis hellerii possesses numerous life history traits and natural history characteristics that are adaptive for invasion of new geographic regions, including: (1) a relatively long larval life (44 days), which facilitates dispersal; (2) rapid growth and maturation within about one year, contributing to a short generation time, which promotes rapid population growth; (3) the ability to store sperm and to produce multiple broods of high fecundity in rapid succession, which favors rapid expansion of founder populations; (4) generalized carnivorous diet, which allows opportunistic exploitation of a variety of food resources; (5) ability to use a diversity of structured habitats, which provides opportunity to exploit a range of habitats, but also suggests that its secretive or cryptic behavior may serve to protect it from visual predators.

The panopeid crab Panopeus margentus is known to inhabit intertidal and subtidal temperate waters of the southwestern Atlantic Ocean, from Rio de la Plata to Mar del Plata, Argentina. The complete larval development of this species is described from laboratory-reared material and compared with known larvae of Panopeus, Eurypanopeus, and Hexapanopeus. A preliminary key for the identification of panopeid megalopae from the temperate waters of the southwestern Atlantic is provided.

Larvae of the sesarmid crab Armases angustipes Dana, 1852, captured from the coast of the state of São Paulo, Brazil, were reared in the laboratory from hatching to the megalopa stage. In this paper, the morphology of the four zoeal stages and the megalopa is described and illustrated. Morphological comparisons are made with all known descriptions for the larvae of Armases including an unpublished description of A. angustipes and of some closely related genera (Aratus and Sesarma). Several differences to the previous description of A. angustipes are shown, and additional characters such as the previously undescribed cephalothoracic setation of the larval stages are described and illustrated. Diagnostic characters are provided to differentiate the American genera Sesarma and Armases.

Although fiddler crabs (genus Uca) have been among the most widely studied organisms with respect to sexual selection, agonistic behavior, asymmetry, and visual and acoustic signaling, the phylogenetic relationships within the genus have remained largely a mystery. After reviewing the systematic history of the genus and its species, including a discussion of the systematic conflicts between two alternative proposals of subgeneric division, a phylogenetic analysis was performed for 88 species on a data matrix of 236 discrete morphological characters. These results were compared to a previously published molecular analysis of 16S ribosomal DNA for 28 species. To a large extent, the uncertainty in the proper taxonomic names for the subgenera can be resolved with these results. The biogeographic history of the genus is discussed, although these results do not provide enough support to allow complete resolution of the deep divergences between Indo-West Pacific and American clades. There is strong morphological evidence to support the monophyly of the broad-front taxa; molecular evidence suggests biogeographic subdivisions.