As The Crustacean Society completes its thirtieeth year of existence, it is time to reflect and appropriately commemorate this anniversary with an appreciation of Raymond B. Manning. This memorial augments the brief biographical sketch presented by Lemaitre and Reed (2000). On the day this issue of Journal of Crustacean Biology is being published, 11 October 2009, Ray would have been 75 and undoubly would have been proud of what the society has achieved in just three decades.

The anatomy of the male reproductive organs of the brachyuran crab Eriphia verrucosa is presented, with a detailed analysis of the histology and histochemistry of the regional structure of the testis and vas deferens. The H-shaped testis is subdivided into three distinct parts: anterior, intermediate and posterior. The vas deferens is continuous with the posterior part of the testis, ends at the gonopore, and is subdivided into three distinct regions: proximal, medial and distal. The anterior part of the testis exhibits convoluted lobules including seminiferous tubules. Whereas the intermediate part of the testis has a simple columnar epithelium, the posterior part of the testis has a simple squamous epithelium. In the proximal and medial regions of the vas deferens, there is a simple cubic epithelium, while in the distal region of the vas deferens there is a high columnar epithelium. Spermatophores are first formed in the convoluted proximal region of the vas deferens and are encapsulated by mainly protein secretions in the distal region. These results suggest that the testis and vas deferens of Eriphia show similarity to the testis and vas deferens of other brachyuran crabs except for some slight differences. During formation of the spermatophores in the vas deferens the spermatozoa are prepared for successful fertilization.

We describe the male reproductive system of the intertidal hermit crab Calcinus tibicen, with emphasis on the sexual apparatus, spermatophore, and spermatozoa. The crabs were collected on the rocky shore of Praia Grande Beach, Ubatuba, southeastern Brazil. The morphological analysis, based on 30 specimens, was made with the use of a stereomicroscope, an optical microscope, and scanning and transmission electron microscopes. The male reproductive system is composed of a pair of juxtaposed testes, located dorsally in the pleon. From each testis emerges a vas deferens that links it to the exterior by the gonopores, located on the base of the fifth pair of pereiopods. The vas deferens has three macroscopically distinct regions that contain spermatophores in different stages of maturation. The spermatophore morphology is similar to that of other members of Paguroidea, having a distal, nearly spherical ampulla containing spermatozoa; an approximately cylindrical peduncle; and a proximal foot connecting the spermatophores. We describe, for the first time, the variability in the spermatophore morphology and size in the three regions of the vas deferens using the type species of the genus Calcinus. The spermatozoa have three main regions (the acrosomal vesicle, the nucleus, and the cytoplasm). The morphological similarity of the male reproductive system of C. tibicen with previously studied species of Diogenidae is an indicative of complex phylogenetic relationships among the members of the genus.

This study examined important stimuli influencing agonistic conspecific pairs of Macrobrachium australiense and how these affected diurnal refuge usage. The results demonstrated key behaviours underlying refuge competition, and have ramifications for how we view the link between conspecific competition and exposure to predation. Different levels of vegetation stalk density were employed to examine the effects of increased refuge quality on the hierarchical interaction. The data analysis demonstrated that the prawns were responding to nearby stimuli which altered detectability, e.g., vegetation density, conspecific size, conspecific movement. Dominants and subordinates both responded to the same stimuli, however, the behavioural response was different. Increasing subordinate size lead to increased dominant activity in all refuges, irrespective of vegetation density. Increasing dominant size caused an increase in subordinate activity in high density refugia but a reduction in low density refugia. The increased activity lead to an overall increase in time spent outside of the refuge for all individuals. Subordinates spent substantially more time outside of the refuge than the dominant individuals. As such refuge competition biases the exposure of individuals to risk, localised changes to this bias, i.e., the size of neighbouring conspecifics, can influence this risk and determine the vulnerability of specific demographics, i.e., smaller individuals, to predation.

In many taxa, social structures are mediated by agonistic interactions and the formation of dominance hierarchies. In crayfish, dominance hierarchies may have evolved as a result of sexual selection, allowing dominant males greater access to females. We examine strategies of investment in agonistic behaviors for males and females of the crayfish Orconectes quinebaugensis in both the reproductive and non-reproductive seasons. We hypothesized that reproductive males would invest more in agonistic behaviors than reproductive females and non-reproductive crayfish. We tested this hypothesis in the laboratory with 4 treatment groups: males and females in the autumn reproductive season and males and females in the summer non-reproductive season, with each group subdivided by size to control for size effects. As predicted, reproductive males spent significantly more time in agonistic behaviors and had significantly more fights reaching maximum intensity than reproductive females, while there was no significant difference in the time spent in agonistic interactions by non-reproductive males or females. We did find that small females in the summer had significantly fewer fights reaching maximum intensity than either males or large females in the summer. However, there was no significant difference in time spent in agonistic interactions or proportion of fights reaching maximum intensity between reproductive males and non-reproductive males, as was predicted by our hypothesis. We did observe a significant effect of size for both males and females in the non-reproductive season, with larger animals spending more time in agonistic behaviors, and with large females having a more fights at maximum intensity than small females; this difference was not recapitulated in the reproductive season. These data indicate that investment in agonism differs by sex and by reproductive status, and the differential investment by sex in reproductive animals may indicate that dominance interactions are under sexual selection in males. However, high investment in agonism by both males and females in the non-reproductive season is not consistent with our hypothesis. Alternatively, the differential investment in agonism by reproductive males and females could be explained by either seasonal changes in the individual costs and benefits of agonism, or by depressed investment by reproductive females.

The scale of variation in population densities and other demographic variables is an important consideration in the design and interpretation of experiments and sampling programs. Here, we studied spatial and temporal variation in populations of Corophium volutator, an intertidal amphipod that is the most abundant macro-invertebrate on mudflats in the upper Bay of Fundy, Canada. Variables that were quantified included density (peaked in mid-summer at 10,000s per m²), proportion juvenile (an index of population structure), sex ratio (female-biased throughout the year), proportion of females that were ovigerous (reproduction occurs between May and August), and fecundity (number of embryos per female). We studied populations at 4 different sites, i.e., separate mudflats, for 1–2 years, and estimated variance components at 3 spatial scales: metres (samples), 100s of metres (transects) and many kilometres (mudflats). Population density exhibited low variation between years (< 10% of the random variation), but showed high variation at our smallest and largest spatial scales (45% between samples, 2% between transects, and 40% between mudflats), i.e., the distribution of C. volutator within a mudflat was aggregated at the scale of metres, but not at that of 100s of metres. Thus, relatively few transects, but many samples per transect, are required for good representation of density on a mudflat. Fecundity was similar between mudflats, but proportion juvenile, sex ratio, and proportion of ovigerous females were strongly affected by site or the interaction between month and site (> 60% of the random variation in each case). The high variation observed between mudflats for most demographic variables demonstrates that several control sites are necessary for measuring natural variation, a critical consideration in studies of environmental impacts.

An analysis of size and reproduction of Heterocarpus ensifer (Caridea: Pandalidae) off the Macaronesian archipelagos (Canary, Madeira, and the Azores islands, northeastern Atlantic) is done. The size range of samples was similar among the archipelagos studied, around 9–39 mm carapace length (CL). The carapace length/wet weight relationship showed a negative allometry in males and varied in females. One-way analysis of regression slopes (b) among archipelagos pointed out significant differences in all groups with the exception of males. Growth parameters indicated that males are smaller in size, but grow faster than females. Growth performance (Φ') estimates varied between 2.69 and 2.81, pointing out a very similar growth pattern among regions. Ovigerous females were present in all months sampled with a mass spawning period in spring and summer, which are the seasons when the water is warmer. Size at maturity was estimated in 22.4 mm CL for the Canary Islands and 25.7 mm CL for Madeira. In general, the life history of this deep-water species is similar in the three archipelagos.

Growth and reproduction of the intertidal dotillid crab Ilyoplax deschampsi were studied in the Ariake Sea, Japan, and life history traits were compared with those of three other species of Ilyoplax occurring in temperate regions. New recruits of I. deschampsi occurred mainly in July and August, and their carapace widths (CW) were about 2 mm. They grew to 4 mm CW by December, and to 7 mm CW by the following July. Some crabs reached reproductive maturity in the second year of life, but others remained immature until the third year. Most crabs did not survive the third year. The main breeding season was from May to July, which ceased earlier than in other temperate species of Ilyoplax. Hepatic and ovarian weights were highest in early May and early June, respectively, and rapidly decreased after August. The earlier breeding of I. deschampsi is thought to be an adaptation for avoiding hot, dry habitat conditions during summer.

Three large brachyuran species are common in the intertidal and shallow subtidal of New England rocky shores: two native crabs Cancer borealis (Jonah crab) and Cancer irroratus (rock crab), and the introduced crab Carcinus maenas (European green crab). For these three co-occurring species in the Isles of Shoals (Gulf of Maine, USA), we compared distribution and abundance to survivorship and prey availability along a depth gradient and examined stomach contents and prey preference. The three species show differences in vertical distribution: Carcinus is more abundant in the intertidal, while both species of Cancer are more abundant in the subtidal. Survivorship of both species of Cancer increases with increasing depth, while survivorship of Carcinus decreases with increasing depth, perhaps corresponding to differential vulnerability to predation by gulls in the intertidal and by decapods and fish in the subtidal. There were notable differences in laboratory prey preference experiments: C. irroratus consumed both small mobile and non-mobile prey (amphipods, small snails, and small mussels), while Carcinus consumed primarily small mobile prey (amphipods and isopods). In contrast, C. borealis consumed larger, heavier bodied prey (larger snails and mussels) but did not eat amphipods or isopods. However, differences in prey preference among crab species were greater than the differences in realized diets. Based on stomach content analysis, the blue mussel Mytilus edulis was the majority component of stomach contents for all three species. Some differences were evident in the remaining diet components: Carcinus was the most omnivorous (> 30% green algae), C. borealis consumed more snails and arthropods, and C. irroratus consumed the most mussels. Overall, species distribution does not track the distribution of the preferred prey of each species; rather, the distribution corresponds with patterns of survivorship, indicating predominant top-down control of crab distribution.

The objective of this study was to clarify the diet composition of the first stage larvae of northern shrimp Pandalus borealis during the spring period of high biological production in the Northwestern Gulf of St. Lawrence (NWGSL). Data collected in spring 2006 revealed that hatching of P. borealis larvae took place in late April and early May during a period characterized by a phytoplankton bloom (mainly species of the genus Chaetoceros) and by an abundance of early stages of mesozooplankton, which demonstrated the onset of secondary production at the sampling site. Gut content examination of stage I larvae sampled at the site and feeding experiments conducted at sea revealed that omnivorous feeding starts at hatching, but a first approximation based on the quantity of pigments present in the larvae suggest that zooplankton is more important than phytoplankton to meet the larvae's energy needs. In addition, field observations of the degree of gut fullness and the low percentage (10%) of larvae with empty guts indicate a high feeding success. Hatching at the time of production of adequate prey could represent a major factor for larval northern shrimp survival in the NWGSL.

Biochemical changes, specifically in hemocyanin and glucose concentrations in hemolymph, glycogen in the digestive gland, were studied throughout the molt cycle in juveniles of Litopenaeus vannamei in a high salinity condition (36), and related to variations in the osmotic capacity of organisms. Increasing hemolymph volume before molting modifies circulating glucose and hemocyanin concentrations acting on the osmotic capacity. Variations in glucose concentrations are indicators of differential energy requirements throughout the molt cycle. Hemocyanin was used as an indirect indicator of the energy consumed by shrimp in various molt processes that affect the osmotic capacity. The co-variability of these metabolites is the result of the biochemical adaptations displayed by shrimp to maintain homeostasis. Their relation to changes in the osmotic capacity is given as a model to understand and predict events associated with molting under hypo-osmotic conditions.

Crustaceans must replace their old exoskeleton with a new, larger one in order to grow and differentiate. During that process a new (pre-exuvial) cuticle is deposited beneath the old cuticle. Since breakdown products from the old cuticle have been reported to be removed from the old cuticle and transported across the new cuticle and hypodermis into the hemolymph, the preexuvial cuticle is presumed to be permeable. However, it has also been reported that intermolt cuticle is a highly impermeable structure that prevents loss of water and ions from the cuticle to the external environment. This study was designed to determine the timing of any change in the permeability of the cuticle of the blue crab, Callinectes sapidus, from the period just preceding ecdysis through the early postmolt period. To test for any changes in permeability pilot studies were performed on pieces of dorsobranchial cuticle from late premolt (D₄) and early postmolt crabs (15 min, 2 h, 12 h and 18 h post-ecdysis) using ³H₂O and an Ussing chamber. Additional permeability studies were done monitoring the movement of p-nitrophenol (pNP) across the cuticle using a more restricted post-exuvial time course (0, 5, 10, 15 and 30 min. post-ecdysis) as compared to premolt cuticle. Results from these studies as well as wash-out studies using tissues pre-loaded with pNP and staining of 1 h post-molt cuticle with OsO₄ suggest that the epicuticle undergoes a transition at or soon after ecdysis that renders it impermeable to water and small molecules. While the precise mechanism for this transition is unknown, it is clear that the resultant alteration in epicuticle permeability during early post-ecdysis allows for the formation of a barrier that prevents osmotic and ionic exchange, allows for the generation of significant hydrostatic pressure, and provides a suitable microenvironment for calcification.

Hemolymph osmolality changes following exposure to abrupt salinity change in the range of 5–40 ppt (T  =  26°C, full air saturation) and upon exposure to air (T  =  23°C, r.h.  =  30%) were investigated in the flatback mud crab Eurypanopeus depressus (Smith, 1869), a dominant species on oyster reefs in Southwest Florida. During salinity trials, hemolymph osmolality of E. depressus ranged from 751 ± 123 mOsmol kg⁻¹ at 5 ppt (214 ± 32 mOsmol kg⁻¹) to 1188 ± 81 mOsmol kg⁻¹ at 40 ppt (1188 ± 29 mOsmol kg⁻¹). In the salinity range of 5–15 ppt E. depressus exhibited a hyperosmotic pattern of osmoregulation while at 30 and 40 ppt it conformed. In all cases stable hemolymph osmotic concentration was reached in less than 24 h. During desiccation trials, hemolymph osmolality of E. depressus ranged from 971 ± 121 mOsmol kg⁻¹ for unexposed crabs to 1132 ± 169 mOsmol kg⁻¹ after 90 min of exposure. The information obtained from this study adds to knowledge of crustacean stress physiology and may give a clearer picture of the important factors involved in population distribution and the consequences of multiple stressors that may affect the crabs or their oyster-reef habitat.

Invasion of an alien freshwater crayfish is newly confirmed in Madagascar. The invasive crayfish is determined as the parthenogenetic Marmorkrebs (marbled crayfish) (Cambaridae: Decapoda) on the basis of morphological features and the fact that all collected specimens were females regardless of their size. As this is a worrisome finding, the public should be alerted so that spread on the island can be prevented before it affects the vulnerable native crayfish biodiversity and the rice field business in Madagascar.

Aiming at a better understanding of the harpacticoid diversity of the South China Sea, sediment samples were taken from Nha Trang Bay (Vietnam) during a sampling campaign carried out in April, 2004. Two female specimens of the monotypic genus Sentiropsis were found. These turned out to belong to a new species, Sentiropsis vietnamensis n. sp., which can be separated from the type species S. minuta by the shape of the setae of the female antennule, size of the seta of the second segment of the antennary exopod, lateral setation of the endopod of the mandible, armature of the arthrite of the maxillule, shape of the seta of the syncoxa of the maxilliped, shape of the seta of the basis of the maxilliped, ventral spinular ornamentation on the posterior half of the genital double-somite and fourth urosomite of the female, P1ENP1∶P1ENP2 length ratio, armature formula of the female P5EXP, shape of the apical setae EXP3 and ENP2, length ratio of the outer spines of P4EXP1 and EXP2, the shape and size of the endopodal lobe of P5, and length of the apical seta on the P5 endopodal lobe. The diagnosis of the genus is amended.

The present paper reports six genera nine species of Palaemonidae collected from Clipperton Island, eastern tropical Pacific, including three new species of the pontoniine genus Chacella: C. bicornuta, C. quadricornuta, and C. sexicornuta. We provide a key to identify all the six known species of Chacella.

This study was conducted to better understand the habitat requirements and environmental limiting factors of Syncaris pacifica, the California freshwater shrimp. This federally listed endangered species is native to perennial lowland streams in a few watersheds in northern California. Field sampling occurred in Lagunitas and Olema creeks at seasonal intervals from February 2003 to November 2004. Ten glides, five pools, and five riffles served as fixed sampling reaches, with eight glides, four pools, and four riffles located in Lagunitas Creek and the remainder in Olema Creek. A total of 1773 S. pacifica was counted during this study, all of which were captured along vegetated banks in Lagunitas Creek. Syncaris pacifica was most numerous in glides (64%), then in pools (31%), and lastly in riffles (5%). According to logistic regression analysis, S. pacifica was mostly associated with submerged portions of streambank vegetation (especially overhanging vegetation such as ferns and blackberries, emergent vegetation such as sedge and brooklime, and fine roots associated with water hemlock, willow, sedge, and blackberries) along with low water current velocity and a sandy substrate. These seemingly favorable habitat conditions for S. pacifica were present in glides and pools in Lagunitas Creek, but not in Olema Creek.

The Antarctic circumpolar ascidian Distaplia cylindrica harbors individuals of the amphipod Polycheria antarctica form acanthopoda that live in domiciles excavated by the amphipod. There was no evidence this amphipod consumed its host ascidian tissues. This burrowing association with D. cylindrica may provide an important structural or chemical refuge from prospective fish predators.