We examined whether color patterns of a marine crustacean may serve to distinguish between individuals and to successfully identify individuals after one molt. Digital images of the rock shrimp Rhynchocinetes typus were digitally processed in order to obtain their diffraction pattern by means of Fast Fourier Transformation (FFT). All diffraction patterns were correlated with a phase-only filter using images of rock shrimp before and after one molt. To determine the degree of similarity of color patterns among rock shrimps, correlation of diffraction pattern was performed. This approach showed that among shrimps the color pattern of the cephalothorax is mainly homogenous (∼83%) in both distribution and intensity. However, the observed degree of variability (∼17%) was sufficient to distinguish between individuals. Furthermore the general color pattern of each individual persisted after one molt and all 14 individuals could be recognized based on their color pattern. It is concluded that this non-intrusive method for distinguishing among shrimp individuals may be a useful tool that could be developed and used in the future instead of expensive and intrusive tagging techniques.

Methods for the identification of individual crustaceans are needed in many types of studies. Snow crab (Chionoecetes opilio) individuals have distinctive natural patterns of tubercles and spines on the carapace. The results of a double-marking experiment using these natural markers along with genetic (microsatellite) markers confirm that natural markings are a reliable means of recognizing individuals within groups of tens to hundreds of snow crabs. These natural markings are persistent through at least two molts. They have already demonstrated their usefulness in laboratory studies of molting and mating and could be applied to a wider spectrum of investigations. A cursory examination suggests that similar carapace features could be used to identify individuals in other crustacean species as well.

The male gonopores, internal male reproductive apparatus, and spermatophores of the Mediterranean hermit crab Clibanarius erythropus are described, using interference phase microscopy and scanning electron microscopy. A discussion on the relationship between the gonopore morphology and the different kinds of setae accompanying them, and the reproductive biology of these crabs is presented. Each testis merges into a tubular duct made up of four zones: 1) the collecting tubule with free sperm; 2) the proximal zone, where the ampulla of the spermatophore starts to be formed; 3) the medial zone, where the ampulla is completed, the stalk lengthens and the pedestal is formed; 4) the distal zone, where the mature spermatophores are stored. In the mature spermatophore the two halves of the ampulla meet at the distinct lateral ridge. Sizes of the different parts of the spermatophore are given and their morphology described. The importance of the morphology of the paguroid gonopore, male reproductive system, and spermatophore is confirmed for phylogenetic studies within the Paguroidea and Anomura.

The sexual behavior of the hermit crab Coenobita compressus was studied. The size, gastropod shell species, and sexual behavior of males measured in terms of successful or unsuccessful mating (assessed by spermatophore transfer) are compared, as well as the role of these variables in male-male encounters for the access to females. Since female receptivity (assessed as degree of egg development) could also influence male mating success, the relative number of receptive and unreceptive females that had or did not have spermatophores is used to evaluate whether unreceptive females were induced to mate. We assessed how frequently receptive and unreceptive females were present in the population. An experiment determined if males were able to grab females according to female sexual receptivity. The results show that: 1) behavior and type of gastropod shell in males is not related to mating success; 2) large males won against small males during contests for the access to females; 3) only some receptive females (actually, the less common in the population) received spermatophores even when males tried to mate with receptive and unreceptive females; and 4) female behavior determined the outcome of mating success. These results indicate that male size is important only during male-male competition but not during female choice. Our results also suggest an active role of female behavior in determining the mating outcome and that males are unable to force females to mate, unlike other species in which females, receptive or not, are unable to evade male sexual assaults.

In Paracerceis sculpta, a Gulf of California isopod, α-males usually defend aggregations of breeding females within the spongocoels of intertidal sponges. Breeding isopods are also found in habitats other than sponges, but interactions among individuals in these locations are poorly known. To investigate plasticity in male-male interactions associated with mate acquisition in breeding habitats other than sponges, we examined the behavior of pairs of α-males in two distinct environments; those in which breeding sites were absent, but females were present, and those in which both breeding sites and females were absent. We established males as residents in the presence and in the absence of females by allowing them to occupy arenas for 1 h before intruders were introduced. Residents and intruders engaged in significantly more total acts and grappled more in the presence of females than when females were absent. In the presence of females, residents became active first in most cases, and gripped females more than intruders. Latency to activity was significantly longer when receptive females were present than when they were absent. However, residents seldom interacted with intruders when females were lacking. Our results suggest that in locations other than sponges, α-males compete for females and can recognize their status as residents and as intruders. These results also suggest that, as in many vertebrate and invertebrate species, P. sculpta α-males attempt to mate opportunistically, and that contests for mates in atypical breeding habitats may be common in nature. We discuss the importance of distinguishing rare and highly contingent behaviors from those likely to represent adaptive behavioral plasticity, and we propose a simple criterion of commonality for their identification in behavioral analyses.

Reproductive biology of the black land crab, Gecarcinus ruricola (Linnaeus, 1758), has been studied in the San Andres Archipelago in the Western Caribbean, on the islands of San Andres and Old Providence. Both sexes become mature at about 50 mm maximum carapace width, and very few specimens below this size take part in the annual breeding migration. In females the ovaries mature progressively from January to April, and laying occurs from May to July. There is no evidence that individual females lay more that once in a year. The breeding migrations were monitored in 2003 and 2004 by recording specimens crossing the coast road (running 50-100 m from the upper shore). On both San Andres and Old Providence migration was limited to specific stretches of the western shores. On both islands migration occurred from late April to July, intensity varying with time. Migration peaks were not consistent between islands or years, and could not be clearly linked to environmental factors. Migrating crabs were mostly female (> 80%), and a proportion were bearing ripe eggs: on San Andres ovigerous female predominated. Thus some females mated and laid eggs on the landward side of the coast road, others on the seaward side. Migrating females were on average larger than migrating males, in contrast to the situation in the non-migrating populations. Log egg number varied isometrically with log carapace width (slope ∼3.0): for 70 mm CW the calculated fecundity was 85,000 eggs. Percentage reproductive investment, based on dry weight, ranged from 1.7 to 9.8%, with a mean of 4.95%. Recruitment was only observed once, with a mass return of megalops to Old Providence in June 2004. All evidence points to very irregular recruitment.

Munida gregaria is a galatheid very abundant in coastal waters of southern South America playing an important role in the trophic webs of the subantarctic coastal ecosystem. Different reproductive aspects of this species were studied from samples obtained by coastal trawlers between September 1997 and December 2000, which allowed the analysis of a total of 10,868 crabs. The reproductive period started in June, and females with small clutches composed of non-fecundated eggs were found in many cases. The size of clutches increased during the reproductive period, and the simultaneous presence of eggs at different stages of development was observed in the same female. In part of the population, larval hatching started in September, after which females mated again. These embryos hatched between late November and mid-December. Females reached physiological maturity between 9 and 12 mm CL and males between 6 and 8 mm CL. Fecundity was initially low (less than 500 eggs/female), and clutches were completed during the reproductive season, until a maximum of 7545 eggs. During the reproductive season males migrate to shallow waters where they gather for mating.

The size of the western rock lobster broodstock is variable over the range of the Western Australian fishery, due to regional differences in the density and length structure of the stock and the female's size at maturity. Management regulations do not currently discriminate in the protection afforded to the broodstock in the different regions. This study has examined whether regional and size differences in early egg diameter, phyllosoma length at hatch and phyllosoma competency, are related to lipid class and fatty acid composition, protein composition and water content in late stage eggs and early stage phyllosoma larvae. A positive relationship, particularly to phyllosoma competency, would have management implications for the protection of broodstock in different parts of the fishery. Females were sampled in three size groups captured in two sampling regions (Abrolhos Islands 60-70 and 80-90 mm CL; coastal 80-90 and > 95 mm CL). Mostly, eggs and larvae from different maternal size classes and regions were not significantly different with respect to lipid class and fatty acid composition, protein composition and water content, and larval competency. The lipid classes of eggs differed significantly (P < 0.02) between the three maternal size-classes; fatty acids differed significantly between both eggs and phyllosoma grouped by maternal catch site and size-class (P = 0.02 and 0.003, respectively); and there was no correlation between biochemical differences and larval competency. These results imply that maternal identity and subsequent diet may have a greater influence on larval competency in P. cygnus than the maternal attributes (size and capture site) that were tested.

Larval development time is a critical factor in assessing the potential for larval transport, mortality, and subsequently, the connectivity of marine populations through larval exchange. Most estimates of larval duration are based on laboratory studies and may not reflect development times in nature. For larvae of the American lobster (Homarus americanus), temperature-dependent development times have been established in previous laboratory studies. Here, we used the timing of seasonal abundance curves for newly hatched larvae (stage I) and the final plankonic instar (postlarva), coupled with a model of temperature-dependent development to assess development time in the field. We were unable to reproduce the timing of the seasonal abundance curves using laboratory development rates in our model. Our results suggest that larval development in situ may be twice as fast as reported laboratory rates. This will result in reduced estimates of larval transport potential, and increased estimates of instantaneous mortality rate and production.

We performed the first cladistic analysis of Metanephrops, the most diverse extant genus of clawed lobster, using a morphology-based data matrix of all 20 species of Metanephrops and 35 cladistically informative characters, all external hard parts. Unweighted cladistic analysis corroborates previous studies that indicated that homoplasy is rampant in the evolution of clawed lobsters. Only 5 of the 68 synapomorphies identified by the analysis are unambiguous, unreversed synapomorphies. Recent species of Metanephrops have traditionally been divided (non-cladistically) into four morphology-based groups. Cladistic analyses support the traditional, arafurensis, Atlantic/binghami, and japonicus groupings; these groups are monophyletic. The thomsoni group is not supported by the cladogram. The (two) oldest known fossil Metanephrops species occur in Late Cretaceous, shallow marine rocks of the eastern/Atlantic side of the Antarctic Peninsula. The stratigraphic and geographic occurrences of these fossil species are the basis for the previously hypothesized, Late Cretaceous, southern high latitude origin of Metanephrops. Cladistic results corroborate that Metanephrops originated in the southern high latitudes. The cladistically most plesiomorphic single species, the recent M. challengeri, and the next most plesiomorphic species, the Late Cretaceous M. rossensis, are both known from the high southern latitudes. Likewise, the most plesiomorphic species group, the binghami group, is best known from the high southern latitudes.

Numerous specimens of the genus Munidopsis from the East Pacific, and including the East Pacific Rise (EPR), are reviewed using morphological characters and mitochondrial cytochrome oxidase subunit I (COI) sequences. Six new Munidopsis species from the East Pacific are described (M. bracteosa, M. hirsuta, M. kensmithi, M. scotti, M. segonzaci, and M. tiburon), and the status of M. recta is revised. A seventh new species (M. vrijenhoeki) from Fiji Basin (SW Pacific) is also included. A combined morphological and molecular analysis revealed that the most common species on the EPR is Munidopsis recta. Most of the new species can be differentiated from closely related species by subtle morphological characters, which correspondingly match the molecular phylogeny and large molecular divergence, confirming the existence of sibling species in the genus Munidopsis. Most Munidopsis individuals formerly considered M. subsquamosa from the East Pacific Rise appear to be members of M. recta. One potential sister taxa to M. recta is M. bracteosa, which is found at the Juan de Fuca hydrothermal vents, the Mendocino Fracture Zone, and a Monterey Bay whalefall. Our findings suggest that Munidopsis populations are tightly interconnected between distant and discrete locations, and challenge models for the predicted dispersal of these species. Additional sampling of Munidopsis populations on localized habitats (wood, hydrothermal vents, and whale falls), as well as intervening abyssal areas, are required to fully understand the complex evolutionary history and diversity of this group.

Virilastacus retamali, a new species of burrowing parastacid, is described from the peatland in Rucapihuel located along the Coastal Cordillera from the province of Osorno, southern Chile. This is the third species of the genus Virilastacus described to date. It differs from V. araucanius and V. rucapihuelensis in the following morphological characters: 1) large eyes; 2) short rostral carina; 3) long antennal scale with prominent spine at the distal end of its external margin; 4) basal podomere of the antennula with a prominent ventral spine; 5) posterior plate of the epistome bears a cluster of prominent anterolateral tubercles; 6) ventral surface of the ischiopodite of the third maxilliped with a band of prominent tubercles and abundant pilosity; 7) U-shaped cervical groove; and 8) subtriangular telson. Finally, the habitat also differs from that of congeneric species, with V. retamali inhabiting a geogenous peatland whereas the other two species inhabit semi-marshland. We also present a complete phylogeny of the Chilean freshwater crayfish showing the distinct position of this new species. Finally, we assess all the Chilean species for conservation status using the IUCN Red List Criteria.

A species of squat lobster, Munidopsis kermadec new to science is described and illustrated from a hydrothermal vent area in Brothers Seamount, Kermadec Volcanic Arc, Southwest Pacific Ocean. It is distinguished from the allied Munidopsis lauensis, by the shape of rostrum, the erectness of eye spines, structure of the sixth abdominal segment and dactyl morphology of P2-4. This new record increases the number of species of Munidopsis reported from Southwest Pacific vent fields to five. A key is provided to distinguish the vent associated Munidopsis. New records of M. lauensis and M. sonne from Brothers Seamount are also reported here and this extends their distribution further south to the western Pacific. The habitat of the new species is briefly described. A note on the Munidopsis diversity in West Pacific vent fields is also provided.