We examined mating behaviour in the harpacticoid copepod Tube battagliai Volkmann-Rocco, 1972, in particular the process of delivering spermatophore seminal contents to the female urosome. Labelling using 4′6′ diamidino-2-phenylindole (DAPI) coupled with two-photon confocal laser scanning microscopy successfully visualised the spermatophore and female internal reproductive system. Sections of the female urosome were imaged to examine seminal fluid stores. The female tissues were found to auto-fluoresce as red emission under green excitation, requiring no additional tissue labelling. DAPI-labelled seminal fluid stores were identified within the female reproductive system. The details observed agreed with previous descriptions of copepod reproductive anatomy and of spermatophores. Specimens cultured under pH 8.10 and a simulated ocean acidification scenario (pH 7.67) were compared for changes in reproductive anatomy and spermatophore size and site attachment. No differences were observed in spermatophore attachment or the female reproductive system but spermatophore size was reduced significantly at pH 7.67 compared with pH 8.10. This size reduction was, however, in proportion to an overall reduction in female body size at reduced pH. Confocal microscopy is shown here to be a valuable tool to investigate detailed reproductive processes in copepods.

Alpheidae are a highly diverse group of carideans with various life histories. They are known to possess specialized body forms and appendages, form facultative and obligate symbiotic relationships, and even exhibit complex behaviors like eusociality. This study represents the first documented association between the alpehid shrimp Alpheus rapax Fabricius, 1798 and the gobiid fish Myersina macrostoma. An undocumented behavioral display was observed in eight A. rapax individuals. The display was only performed in newly molted individuals while within their respective burrows in the presence of light. The display consisted on the following repetition: shrimp shifted its entire body forwards, with the cephalothorax angled downwards with respect to the pleon and both chelipeds extended forwards and towards each other; body jerked rapidly backwards with pleon curled and walking pereiopods extended; cephalothorax angled upwards, while the chelipeds were spread apart and moved backwards; and continuous undulations of pleopods. The display was hypothesized to either contribute to physiological requirements post molting or as a dishonest signal.

Limnoperna fortunei, or the golden mussel, invaded South America through the Río de la Plata estuary in 1991. The size-selective predation on this bivalve by freshwater decapods crustaceans could be an important part of selective trophic behavior because shell sizes are correlated with the flesh contents and their resistance to being broken. The aim of the paper was analyze the size selective predation by the freshwater crab Zilchiopsis collastinensis Pretzmann, 1968 on different sizes of the invasive bivalve L. fortunei. We considered three combinations (AC, AD and BD) of equal numbers of three different shell lengths of mussels: A (small) = 7 to 10.99 mm, B (medium) = 11 to 14.99 mm and C= 15 to 18.99 mm and D= 19 to 22.99 mm (large). These combinations were offered to each adult female intermolt crab individually, and the number of mussels remaining was registered after one, two and 24 hours to evaluate prey-size selection. After this trial, ten female crabs were recorded preying on two different sizes of mussels (A and C) in combination (AC), and we registered the selective feeding behavior (feeding methods and time of predation) with each size of mussel. The results indicated that female crabs ate different sizes of golden mussels, showing an increased consumption of large mollusks after 24 hours, although these sizes demanded higher predation times. Large mussels were encountered at the first time (one and two hours) by the crabs, and these mussels were consumed successfully in the combination AD. These female crabs showed several alternative strategies to access the flesh and were efficient in handling large mussels, presenting an advantageous degree of plasticity for their predatory responses. L. fortunei could be a new food resource for adult Z. collastinensis females, and it could be responsible for a new interaction “native predator-invasive prey” in the system.

Adults of three fairy shrimp species are present in Thailand from February through June in ephemeral waters (ponds, roadside canals, and rice field ditches) filled mostly by the rain. Branchinella thailandensis is of interest in aquaculture because it reproduces rapidly and has high nutritional value. However, no detailed studies on its reproductive biology are available. Anatomical analyses of male and female genitalia were studied with light microscopy and SEM. Shrimp were reared in the laboratory at 28 ± 1 °C in aerated, potable water using the alga Chlorella sp. as food. One female and two males were placed in each of ten 1-L observation containers and the female reproductive stages were monitored every hour over six days. Branchinella thailandensis exhibits zygogenetic reproduction and oviparity, where fertilization is direct and internal; the brood pouch shows an undifferentiated amplexial groove. Males and females reach maturity on days 7 and 8 after hatching, with a mean standard length of 10.3 and 12.2 mm, respectively. Males have unique spines on the gonopods, with a tip on a socket-like base; accessory glands were not evident in histological sections. Females have biramous ovaries; the shell glands are organized in two paired, bilateral clusters, in which the glandular unit is formed by two gland-cells and a single duct. After six complete reproductive cycles, the mean total duration of the reproductive cycle was ∼24.0 h (N = 60). The total duration of the reproductive cycle and egg production increased with age (subsequent reproductive cycles). No oösorption in unmated females was observed, and the oöcytes passed to the ovisac independent of copulation. Our results confirmed that Stage 3 is the longest reproductive stage in anostracan females. Branchinella thailandensis produces typical freshwater anostracan sculptured eggs, and belongs to the fairy shrimp group without a sub-cortical space beneath the egg shell.

Caridean shrimp exhibit a wide variety of sexual and mating systems, and many species are well studied. Gnathophylloides mineri Schmitt, 1933 is a small, circumtropical symbiont of various species of sea urchins. Very little is known about the reproductive ecology of this species. Field surveys of a Jamaican G. mineri population showed that the reproduction occurred throughout the year, with a consistently high (>80%) percentage of ovigerous females in all seasons. The female: male sex ratio (1.31 : 1) was not significantly different than 1:1. Typically 1 to 3, and no more than 5, shrimp per urchin were observed at our field sites, a lower density than at other Caribbean locations where larger urchins support greater numbers of smaller individual shrimp. Gnathophylloides mineri Schmitt, 1933 occurred predominantly as pairs, and 85% of those pairs consisted of one male and one female. Such strong pair-bonding suggests the shrimp may be socially monogamous, unlike polygynous populations elsewhere that have greater numbers of shrimp per urchin and highly femalebiased sex ratios. The duration and fidelity of the pair bond in Jamaican G. mineri, however, is uncertain. Despite the high incidence of heterosexual pair-bonding, 74% of females with no male partners were ovigerous, suggesting that males engage in either extra-pair mating behavior or sequential monogamy. Given the circumtropical distribution and ecological variability among populations of G. mineri, the study of this species can provide valuable insight into the accuracy of current caridean reproductive models.

The pandalid Plesionika izumiae Omori, 1971 is widely distributed in the west Pacific regions. This is a relatively common shrimp in the coastal waters of Japan, except off northern Honshu and Hokkaido, and is commercially important for small-scale bottom seine fishery. The growth patterns and longevity of P. izumiae were estimated in Kagoshima Bay, southern Japan, using time series of the length-frequency distributions during February 2007 to January 2011. Carapace length ranged from 4.4–14.5 mm in males and 4.0–14.7 mm in females. Both males and females were first recruited in autumn (October—November) with modal size around 7.0 mm carapace length. The growth was best described by the Pauly and Gaschütz equation as L_t = 11.95[1 - exp{-3.991(t/12 - 0.118) - (2.866/2π) sin(2π(t/12 - 0.955))}] for males and L_t = 12.73[1 - exp{-4.084(t/12 - 0.142) - (2.646/2π) sin(2π(t/12 - 0.912))}] for females. Females grew faster and reached a larger size at the same age than males. Monthly growth rate was lower during December to February and higher during March to May in both sexes. The longevity of this species was estimated to be around 18 months for both sexes. The relationship between carapace length and body weight indicated negative allometric growth in males and positive allometric growth in females.

While much literature exists on the ecology and ecosystem impacts of signal crayfish, Pacifastacus leniusculus (Dana, 1852), as an invasive species, little information exists on the ecology of this species in its native range in the Pacific Northwest, USA. Signal crayfish (P. leniusculus leniusculus) were collected from the Umatilla River in northeastern Oregon, USA, where they are native. Collecting occurred during the summer at 13 sites spanning the longitudinal gradient of the river to examine the relationship between density and size of individuals and environmental factors at two spatial scales. At the reach scale (100 m²) the density of young-of-year (YOY), and age 1 female and male crayfish was positively associated with substrate size. Additionally, age 1 female and male crayfish density was negatively associated with the amount of crop agriculture. Substrate size was also important in determining the density and size of crayfish at the microhabitat scale (<1 m²) with greater densities and larger size (for age 1 females and males) with larger substrate. Other factors influencing density at the microhabitat scale included Froude number for YOY and age 1 females with higher densities at lower Froude numbers (indicative of tranquil flows) and water depth for age 1 males with higher densities at greater depth. Our results indicate that substrate size is one of the most important drivers of the distribution and density of signal crayfish in the Umatilla Basin at multiple spatial scales. Understanding the habitat requirements and ecology of this species in its native range is important as agricultural intensification resulting from the development of biofuel technology and increasing human population size and the threat of invasive crayfish species might greatly influence the distribution, abundance, and management of the species of Pacifastacus in their native range in the near future.

The molting growth pattern of the Japanese mitten crab Eriocheir japonica (de Haan, 1835) was investigated under laboratoryreared conditions. Crabs were individually reared in freshwater for 5 years in a constant temperature room at 23–25°C. The age after metamorphosis and instar number were recorded for each molt, and the intermolt period was calculated for each crab. Carapace width (CW) was measured and the percentage molt increment was calculated. Eleven crabs reached a CW > 10 mm. Each growth curve (ageCW relationship) had two phases in the juvenile stage. Growth rate gradually decreased in the younger phase before changing to nearly constant in the older phase. During the younger phase, the percentage molt increment decreased from 25.0%–38.1% to 6.0%–26.2% (ca. 2–10 mm CW, 1st to 11th instars), and the intermolt period increased from 4–9 days to 40–300 days (ca. 2–20 mm CW, first to thirteenth instars). During the older phase, both parameters became broadly flat but showed marked fluctuations. Crabs reached minimum adult size (ca. 35 mm CW) or the adult stage at 2–4 years after metamorphosis. The instar numbers required by E. japonica to reaching maturity was more than that required by other brachyuran species. The adult stage appeared after the twentieth instar in females, and crabs reached their minimum adult size during the sixteenth to twenty-first instars. After puberty, one female continued molting growth. This suggests that adults could live longer and grow larger in size if they remain in a freshwater environment.

Species composition, reproduction and body size of mud crabs, genus Scylla de Haan, 1833, were investigated using gill nets from October 2008 to October 2009 in Urado Bay, Japan. Three mud crab species were identified in the area, with S. paramamosain Estampador, 1949 being the dominant species (74% of the catch), followed by S. serrata (Forskål, 1775) (23%) and S. olivacea (Herbst, 1796) (3%). We found temporal changes in species composition with abundances of S. serrata increasing towards the summer season. Ovigerous females of S. paramamosain and S. olivacea occur between January and October, peaking in the warm (May-July) and rainy (June-July) seasons, but we found no berried females of S. serrata. The female-biased sex ratios of S. paramamosain and S. serrata, and the larger body size of females during the period from autumn (November) to early spring (April), suggest that large gravid females may have migrated offshore before the spawning season. The mean body size of females and males of S. paramamosain and S. serrata tended to increase and the mating activity was high between May and October, showing the moulting and growth season.

Total protein, lipid and carbohydrate variations for the whole embryonic development were measured every 48 hours in samples of eggs of Macrobrachium occidentale (Holthuis), 1950, a small freshwater caridean. Proteins are the main component followed by lipids and carbohydrate only as minor constituent. Most required energy seems to come from metabolism of fat, which was profusely depleted during the whole of development while proteins seem to be mostly utilized for tissue formation. Details of morphological changes of every developmental step are also presented and a comparison of present results with works of other prawn eggs is discussed.

The order Stomatopoda comprises a large number of modern representatives but only a relatively small number of fossil representatives. This low number of fossil mantis shrimp could be attributed to the fact that, in general, they have a poorly calcified cuticle, and their body is highly articulated and flexible, as compared to decapods, which may lead to a high rate of disarticulation and decomposition. A new genus, and species of Cretaceous stomatopod is described from a clastic, shallow water environment, of what today is north-east Texas. Nodosculda fisherorum n. gen. n. sp. is a relatively small mantis shrimp characterized by strong, defensive ornament on the carapace, thorax, and pleon. Although preserved in clastic sediments, these specimens show a remarkably good state of preservation. Articulated pleopods with attached setae, and muscle fibers have been identified on the pleon.

Goniodromitidae is an extinct family of primarily Jurassic and Cretaceous crabs that are found mainly in Europe. Herein, we report upon a diversity hotspot for goniodromitids from the Koskobilo quarry in northern Spain exposing mid-Cretaceous (Albian/Cenomanian) coral reef limestones. Five species of goniodromitid are described and discussed: Distefania incerta, D. renefraaijei n. sp., Eodromites grandis, Goniodromites laevis, and Navarradromites pedroartali n. gen., n. sp. Furthermore, Distefania centrosa is herein synonymized with D. incerta. Eodromites grandis was previously known only from the Late Jurassic, resulting in a time gap of 45 Myr. Other species of decapod with long time ranges are known. Additionally, the Spanish representatives of Eodromites grandis are the only Cretaceous specimens known from this genus. Species of the genera Distefania, Eodromites, and Goniodromites were predominantly found in coral/sponge limestones from the Jurassic and Cretaceous of Europe and were important for the survival of the family into the Cretaceous and indirectly into the Paleocene.

Biomineralized structures are hybrid composites formed and stabilized by the close interaction of the organic and the inorganic phases. Crayfish are good models for studying biomineralization because they develop, in a molting-mineralization cycle, semi-spherical mineralized structures referred to as gastroliths. The organic matrix of these structures consists of proteins, polysaccharides, and lipids. Chitin is the main polysaccharide and is concentrically arranged as fibrous chitin-protein lamellar structures. Although several proteins and low-molecular weight phosphorylated components have been reported to be involved in gastrolith mineralization, the occurrence and role of proteoglycans have not been fully documented. We have immunologically analyzed the proteoglycans in gastrolith matrix extracts and histological cross-sections of the gastrolith, and the forming epithelium during premolt and postmolt stages. The results indicate that gastroliths contain proteoglycans that have dermatan-, chondroitin-4- and 6-, and keratan sulfate glycosaminoglycans. These macromolecules are closely associated with the mineral phase of the gastrolith and are easily removed by decalcification procedures. There is also evidence to indicate that epithelial secretion of some of these molecules is temporally regulated during the molting cycle. However, the precise role of these macromolecules in the calcification and stabilization of the amorphous calcium carbonate phase of the gastrolith remains to be established.

The biodiversity of Bathynellacea, a globally important group of groundwater crustacean, remains poorly known and understood. The objectives of this work were to increase the molecular information of bathynellaceans in order to test: 1) its usefulness solving taxonomic problems; and 2) evaluate the extent of cryptic speciation in a morphologically constrained clades from populations that have already been studied using only morphological methodology, contributing in this way to estimate the real diversity of Spanish subterranean fauna. We employ the COI barcode region to provide a preliminary assessment of the genetic subdivision, mtDNA lineages, of the genus Vejdovskybathynella, Bathynellidae, which has a restricted distribution to a karst system of Burgos (Spain) and was initially identified as a single species by morphological evaluation: Vejdovskybathynella edelweiss Camacho, 2007. We also studied the mtDNA lineages within six morphospecies of Parabathynellidae, five species belonging to Iberobathynella, a genus of wider distribution in the Iberian Peninsula, and one species belonging to the cosmopolitan genus Hexabathynella. The analyses of molecular data demonstrate the presence of highly divergent genetic units. We identify three divergent mtDNA clades, that may represent cryptic species that had gone unnoticed and possibly correspond to undescribed new species. We present a first preliminary molecular phylogeny of Bathynellacea, using three genera of Parabathynellidae and one genus of Bathynellidae, and one member of Anaspididae Thomson, 1893 as an out-group. The results of this study provide the first molecular data complementing the existing morphological knowledge to try to resolve the relations among Spanish genera and species of Bathynellacea through phylogenetic studies. Based on the results, we conclude that the evolutionary scenario of this special group of subterranean crustaceans cannot be revealed using only morphological information due to the presence of cryptic species.

The extant genera of the spinicaudatan clam shrimp family Limnadiidae are revised using morphological criteria built on previously published molecular analyses. The combined analyses demonstrate the presence of eight well defined genera, two of which are new to science and one (Paralimnadia) that is resurrected. We present the description of the new genus Afrolimnadia and the new genus and species Calalimnadia mahei n. sp. described from Mauritius Island. Both molecular and morphological data strongly support eight genera: Afrolimnadia n. gen., Calalimnadia n. gen., Eulimnadia, Imnadia, Limnadia, Limnadopsis, Metalimnadia and Paralimnadia.

Two new species of Triconia in Oncaeidae, including both sexes of Triconia constricta n. sp. and females of Triconia pararedacta n. sp., are described from south of Jeju Island in the East China Sea. Triconia constricta belongs to the dentipes-subgroup of Triconia characterized by the absence of integumental pockets on the anterior surface of the labrum. It is distinguished from the closely related species of this subgroup, T. dentipes (Giesbrecht, 1891), T. elongata Böttger-Schnack, 1999, and T. giesbrechti Böttger-Schnack, 1999, by the following combination of morphological features in females: 1) lateral margins of genital double-somite in dorsal view slightly constricted at midlength; 2) P5 with very long outer basal seta, reaching beyond paired secretory pores on posterior part of genital double-somite, as well as distinctive length ratios of exopodal setae; in both sexes; 3) length ratios of caudal setae, and 4) relative spine lengths on distal endopodal segments of swimming legs 2 to 4. Triconia pararedacta is a member of the conifera-subgroup characterized by a dorsal projection on the second pedigerous somite in the female. It differs from females of other species of this subgroup in the following: 1) very small-sized dorsal projection on second pedigerous somite, 2) different length to width ratio of P5 exopod, 3) relative lengths of outer basal seta and exopodal setae of P5, and 4) different length ratio of outer distal spine to distal spine on endopods of P2–P4. Additional character states are proposed for defining the dentipes-subgroup within Triconia and for recognizing three sets of species within the conifera-subgroup.

We describe from the NW Mediterranean Sea a new copepod species of Anthessiidae, Anthessius alpheusicolous, found in association with the snapping shrimp Alpheus macrocheles (Hailstone, 1835). The new species is differentiated from its 40 congeners by the formula of the third segment of the fourth exopod, the number and morphology of the terminal claws on the antenna, the armature of the mandible, and the length of leg 5. A key to the 41 species currently included in Anthessius is presented. The relationship between A. alpheusicolous and its decapod host likely arose through host switching, and the known symbiotic relationships between the species of Anthessius and their respective hosts are reviewed within this frame. Additionally, the synonymy between A. projectus Kim, 1993 and A. kimjensis Suh, 1993 is here reported for the first time.

Up until now, the genus Parvulobathynella Schminke, 1973, had eight species in the world. Of these, three species each are known from South America and Africa, and two from peninsular India. Parvulobathynella macrodentata n. sp. is described herein from the phreatic zone of southeastern India. Interestingly, the new species has striking mandibular affinity with the Brazilian Odontobathynella amazonica Delamare Deboutteville and Serban, 1979. So the mandibular criteria of Parvulobathynella are suitably amended to accommodate the new species and the interrelationships of Parvulobathynella and Odontobathynella, briefly discussed. The paper also provides an updated key to the world species of Parvulobathynella in addition to some ecological notes on the new species.