Sand Crab Research Articles

Acute Toxicity of Monocrotophos on Histological Alterations in the Anomuran Crab, Emerita asiatica (H. Milne Edwards, 1837)

This study characterized the acute toxicity of Monocrotophos on histological alterations in the different organs like gills, Hepatopancreas and ovary of Anomuran Crab, Emerita asiatica. Though Emerita asiatica is not a commercially viable crab, but it plays a vital role in the coastal environment to maintain a stable marine ecosystem. Several steps and precautions measures should be taken to consume these members of the marine food chain to have aunwavering ecosystem and also to protect this species from extinction. Thus, it can be concluded that the use of Monocrotophos which has been legally banned in India is justified. It has been proved by several workers and has been conformed in present investigation that use of this organophosphate causes serious damage to the vital organ of sand crabs gill, hepatopancreas and ovary. The utilization of Monocrotophos should be minimized in the agricultural field area near to the coastal ecosystem.

Mole crab-inspired vertical self-burrowing.

We present EMBUR—EMerita BUrrowing Robot—the first legged robot inspired by the Pacific mole crab, Emerita analoga, capable of burrowing vertically downward. We choose Emerita analoga as a model organism for its rapid downward burrowing behaviors, as it is four times as fast as the most rapid bivalve mollusk. Vertical burrowing in granular media is a challenging endeavor due to the tendency for the media to create upwards resistive forces on an intruder, even during purely horizontal motions. Our robot is capable of vertically burrowing its body in granular substrate primarily through excavation using two leg pairs, which are functionally analogous to groupings of leg pairs of the mole crab. We implement a novel leg mechanism with a sweeping trajectory, using compliant fabric to enable an anisotropic force response. The maximum resistive force during the power stroke is 6.4 times that of the return stroke. We compare robot body pitch and spatial trajectories with results from biomechanical studies of the mole crabs. We characterize the sensitivity of the robot to initial depth, body pitch and leg pose, and propose bounds on initial conditions which predict various burrowing failure modes. Parametric studies utilizing Granular Resistive Force Theory inform our understanding of robot behavior in response to leg phasing and orientation. Not only does this robotic platform represent the first robophysical model of vertical mole crab-inspired burrowing, it is also one of the first legged, primarily excavative small-scale burrowing agents.

Mitochondrial genomes of the land hermit crab Coenobita clypeatus (Anomura: Paguroidea) and the mole crab Emerita talpoida (Anomura: Hippoidea) with insights into phylogenetic relationships in the Anomura (Crustacea: Decapoda)

The infraorder Anomura is a species-rich clade of decapod crustaceans recognized by its remarkable disparity in terms of morphology, anatomy, ecology, physiology, and behavior. This study assembled and characterized the complete mitochondrial genomes of two anomuran species, the hermit crab Coenobita clypeatus and the mole crab Emerita talpoida. The AT-rich mitochondrial genomes of C. clypeatus and E. talpoida are 16,469 bp and 15,810 bp long, respectively, and are composed of 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. A 1,390 bp and 553 bp long intergenic space is assumed to be the D-loop in C. clypeatus and E. talpoida, respectively. Mitochondrial synteny in C. clypeatus is identical to that reported in other congeneric hermit crabs while synteny in E. talpoida is identical to that described for the confamilial mole crab Stemonopa insignis. No major differences occur between the studied species and their respective congeneric / cofamilial species in terms of nucleotide composition and codon usage profiles of PCGs. Selective pressure analysis in PCGs, rarely conducted in anomuran crabs, indicate that all these mitochondrial PCGs experience purifying selection and that this purifying selection is stronger in some (i.e., cox family genes and cob) compared to other PCGs (e.g., atp8). Most of the tRNA genes exhibited a typical ‘cloverleaf’ secondary structure with few exceptions in the two studied species. In C. clypeatus, tRNA-Ser1 lacks the thymine pseudouracil cytosine (TΨC) loop while tRNA-Phe and tRNA-Tyr each exhibit a deletion of the dihydroxyuridine (DHU) loop but not the arm. In turn, in E. talpoida, tRNA-Phe and tRNA-Arg exhibit a deletion of the DHU loop but not the arm while tRNA-Ser1 lacks the TΨC arm. A phylogenomic analysis based on translated PCGs confirms the monophyly of the infraorder Anomura and retrieves most/all relationships at the superfamily and family level previously reported for anomurans. The analysis supports the monophyletic status of the families Albuneidae, Lithodidae, Coenobitidae, and Porcellanidae. In turn, the superfamily Paguroidea, and the families Paguridae and Diogenidae are polyphyletic.

Etnozoologi terhadap Pemanfaatan Hewan sebagai Pengobatan Tradisional di Desa Sambulangan Kecamatan Bulagi Utara Kabupaten Banggai Kepulauan

Traditional medicine is treatment or treatment with ingredients or ingredients in the form of plant, animal, mineral, preparations of galenic or a mixture of these materials whose treatment refers to experience, according to skills from generation to generation, or education/training, and is applied according to the norms prevailing in society. The traditional use of animals is deliberately carried by the community to overcome health problems. The study aims to determine the types of medicinal animals and diseases that can be cured by the use of animals as traditional medicine in Sambulangan Village, North Bulagi District, Banggai Islands Regency. The type of research used in this study is descriptive qualitative, this research was carried out from July to August 2021, located in Sambulangan Village, North Bulagi District, Banggai Islands Regency. The population in this study were all types of animals used as ingredients for traditional medicine in Sambulangan Village. The samples in this study were individuals of each type of animal used as ingredients for traditional medicine in Sambulangan Village. The method of taking sample data is by using the purposive sampling method. Techniques in collecting data using interviews, surveys and documentation. Data were analyzed using qualitative descriptive analysis. The results of the study identified several types of medicinal animals and diseases that could be cured by the use of medicinal animals in Sambulangan Village, North Bulagi District, Banggai Islands Regency. There were 10 types of medicinal animals, namely monitor lizard (Varamussp.), snake (Malayophytonsp.), sand crab (Myrmeleonsp.), carthworm (Lumbricus sp.), honey bee (Apissp.), ayam kampung (Gallus gallussp.), cuscus (Ailuropssp.), snail (Achatinasp.), dubia roach (Blapticasp.), snakehead fish (Channasp.), and diseases that can be treated using these medicinal animals, namely internal diseases in general, liver disease, asthma, heart disease, surgical wounds, cough, gout, ulcers, typhoid, and toothache.

Morphological and molecular characterization of mole crab (Genus: Emerita) in the Cilacap coastlines of Indonesia, with particular focus on genetic diversity of Emerita sp. nov.

Abstract.Bhagawati D, Nuryanto A, Winarni ET, Pulungsari AE. 2022. Morphological and molecular characterization of mole crab (Genus: Emerita) in the Cilacap coastlines of Indonesia, with particular focus on genetic diversity of Emerita sp. nov. Biodiversitas 23: 2395-2404. Previous studies reported Emerita emeritus is the only species of the Genus Emerita inhabiting the coastal ecosystem of the Cilacap District. A recent study reported the presence of suspected new Emerita species living on the Cilacap sandy beach but used a small number of specimens and no reports about genetic diversity. This study used more Emerita samples than the previous study. This study aimed to identify Emerita specimens based on the morphology and the cytochrome c oxidase 1 gene and analyzed the genetic diversity of Emerita sp. nov. Emerita samples were collected from three different beaches in Cilacap District, Central Java, Indonesia. Morphological identification placed the samples into two different morphotypes. Morphotype A was identified as Emerita emeritus. Morphotype B was determined as Emerita sp. nov. Molecular data support the placement of Emerita samples into Emerita emeritus, and Emeritasp. nov. Emeritasp. nov. has haplotype diversity of 0.857±0.057, indicating a high genetic diversity. Haplotype H2 was suggested as the most primitive one because other haplotypes radiated from it. This study concluded that two sympatric Emerita species inhabit Cilacap coastlines, and Emeritasp. nov. has high genetic diversity.

Impact of the acanthocephalan parasite Profilicollis altmani on the fecundity of its crustacean intermediate host, the Pacific mole crab, Emerita analoga

AbstractParasites may influence their hosts in multiple ways, ranging from physiological changes and behavioral modifications, to altering life history traits. One fitness component that is often considered in relation to parasitism is host fecundity. The larval acanthocephalan parasite, Profilicollis altmani, commonly infects the Pacific mole crab, Emerita analoga; yet this parasite's effect on the crab's fecundity is unknown. Consequently, we examined the effects of acanthocephalan parasitism on the fecundity of this mole crab species. Crabs were collected from the swash intertidal zone in Monterey Bay, CA, and the following parameters were quantified: crab body size (carapace length) and weight, egg‐bearing status (nongravid and gravid), egg number and diameter, total volume and weight of egg mass, and their developmental stages (from newly laid eggs to recognizable zoea larval stage). Parasite prevalence, intensity of infection, and body size of larval cystacanths (measured as volume) were assessed. Host fecundity was positively correlated with both body size and body weight. No differences in egg weight were found between uninfected and infected crabs. Similarly, no difference in crab body weight at various embryonic developmental phases was documented between uninfected and infected crabs. Cystacanth volumes in infected nongravid and infected gravid crabs were not significantly different. Our study suggests that the parasite P. altmani does not have any appreciable effect on the fecundity of E. analoga and that female mole crabs undergo normal reproduction and maintain robust population sizes in their natural environments. Our findings thus appear to moderate the pervasive notion of a major impact of parasitism on host reproduction.

Growth and reproduction of the mole crab Hippa truncatifrons in Suruga Bay, central Japan

Growth and reproduction of the mole crab Hippa truncatifrons in Suruga Bay, central Japan

Analysis of changes in the microbial community structure and physicochemical properties during the fermentation of sand crab juice.

The structure of the microbial community during sand crab juice fermentation was analyzed using culture-based methods and high-throughput 16S rRNA gene sequencing. Additionally, the changes in amino acid nitrogen (AAN) and total volatile basic nitrogen (TVB-N) were evaluated. Staphylococcus equorum, Staphylococcus arlettae, Staphylococcus saprophyticus, Salinicoccus amylolyticus and Bacillus cereus were isolated by traditional culture isolation technique. The Good's coverage obtained by high-throughput sequencing was over 99.5%, and the Chao1 and Simpson indices showed small fluctuations, indicating that the species abundance and diversity did not change significantly during the fermentation process, although the abundance decreased. Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacterial phyla observed during fermentation, whereas Aquabacterium, Roseovarius, Muribaculaceae, and Silicimonas were the dominant bacterial genera. The AAN content increased from 0.15 to 0.43g/100mL during the 15-day fermentation, indicating the production of small peptides and amino acids during fermentation. The TVB-N content (25.2mg/100mL) on day 15 indicated slight spoilage of sand crab juice, although the freshness conformed to the production standard. These results provide a theoretical basis for improving the quality and optimizing the production process of sand crab juice.

Toxicity of Refugio Beach Oil to Sand Crabs (Emerita analoga), Blue Mussels (Mytilus sp.), and Inland Silversides (Menidia beryllina).

Monterey formation crude oil spilled from an onshore pipeline and entered the surf zone near Refugio State Beach, Santa Barbara County, California (USA) on 19 May 2015. During this season, early life stages of many marine fish and invertebrates were present. Surf zone water and beach porewater samples were collected during the 4 mo after the spill and 2 yr later for chemical analyses. Elevated polycyclic aromatic hydrocarbon (PAH) and total petroleum hydrocarbon concentrations were observed in surf zone water and porewater near the release point, declining with distance and time. Early life stage toxicity was investigated by conducting 6- and 7-d static renewal bioassays with sand crab (Emerita analoga) post larvae (megalopae) and inland silverside larvae (Menidia beryllina), respectively, and a 48-h blue mussel (Mytilus sp.) embryo development bioassay. Dilutions of a high-energy water accommodated fraction of the Refugio Beach oil and a seawater control were prepared to simulate surf zone PAH concentrations (nominal PAH45 ; 0, 0.5, 1, 5, 10, 50, 100, and 500 µg/L). The PAH45 median lethal concentrations (LC50s), based on measured concentrations, were 381 µg/L for Mytilus sp., 75.6 µg/L for Menidia, and 40.9 µg/L for Emerita. Our results suggest that PAH concentrations in coastal waters of the spill-affected area were potentially lethal to early life stages of fish and invertebrates. Environ Toxicol Chem 2021;40:2578-2586. © 2021 SETAC.

Granular Resistive Force Theory Implementation for Three-Dimensional Trajectories

Modelling interaction forces as bodies intrude into granular media is a longstanding challenge in the design and control of machines that navigate and manipulate these highly complex materials. Granular Resistive Force Theory, or RFT, is a flexible, reduced-order model for predicting intrusion forces on bodies in granular media. 2D RFT describes the forces on a plate whose velocity and normal vectors lie in the same vertical plane. We introduce a 3D RFT method that projects the total velocity vector into two scenarios that can already be described by 2D RFT, which allows us to extend the model into 3D with minimal additional experimental characterization. We then superimpose these independently calculated forces, weighted by experimentally fit scaling factors, to determine the total force on the plate. When applied to discretized convex hulls, this method performs force estimates of arbitrary trajectories in 3D space. The proposed formulation predicts forces experienced by oscillating and circumnutating bodies, motions motivated by mole crab burrowing and plant root growth respectively. This method is well-suited to complement more complex computational tools, such as Discrete Element Method. By expanding the application of RFT to 3D scenarios, a broader set of real-world applications can now be analyzed.

Photosynthetic electron transport rate (ETR) in the littoral herb Launaea sarmentosa known as mole crab in Thailand.

Launaea sarmentosa (Willd.) Sch. Bip ex Kunze (Asteracaeae) is a littoral sand dune herb found in the Indian Ocean region, used as a folk medicine and as a savory vegetable in Thailand. It is in the transition stage from a kitchen & cottage industry to a commercial proposition. Rapid light curves to measure the photosynthetic electron transport rate (ETR) were conducted on the plants over the course of daylight from 6:00 to 18:00 using a PAM fluorometer on plants grown under 50% (nominal) green horticultural and 20% black (nominal) shade cloth and in the open. Plants grown in the open were sun plants. Eopt (µmol photon m-2s-1) decreased slightly under shade cloth (open air: 890 > green shade cloth, 778 > green shade cloth, 713). Launaea shows limited shade adaptation. ETR decreased under shade cloth on both a surface area and Chl a basis (µmol e- g Chl a-1s-1) [open air: 388 > (green shade cloth, 209 = black shade cloth, 263)]. Maximum non-photochemical quenching (NPQmax) was significantly decreased under black shade cloth [(open air: 1.02 = green shade cloth, 0.969) > black shade cloth, 0.694]. ETR showed midday inhibition (9:00-15:00) when irradiance exceeded the Eopt of Launaea. Daily total photosynthetic electron transport was (mmol e- m-2 d-1): open air, 1890 ± 157; green shade cloth, 1620 ± 203, black shade cloth, 1217 ± 143. Green shade cloth has no effect on total daily photosynthetic electron transport of Launaea but offers some protection from desiccation and excessive evapotranspiration. Waterlogging decreases ETR by about 40%. Launaea can be grown watered with brackish (½ seawater) water unlike many other vegetables. Launeae is a physiologically undemanding cottage industry/market garden crop suitable for sandy coastline fishing communities.

Facile and green approach in managing sand crab carapace biowaste for obtention of high deacetylation percentage chitosan

Sand crabs are one of the most important and abundant invertebrates in the sandy beaches ecosystem of the Pacific sea. After death, this crustacean generates large quantities of solid waste in the form of body carapace (exoskeleton), which has caused pollution and affecting human life quality. The carapace is primarily composed of chitin and proteins. Therefore, this bio-waste could be employed as a potential source of chitosan, providing health benefit to human. Thus, in this work, samples with different deacetylation percentage of chitosan were obtained. Separate treatments were applied to the carapace and the ends. The microscopic particles are flake-like structures with size range of 110 – 220 µm and uniformly distributed porosity was found in the end samples. An orthorhombic crystal structure (crystallinity of 30%) was observed, similar to the sample reported in literature. Ash, humidity and insoluble matter percentage confirmed the quality of chitosan for potential biomedical applications.

Life history and demographic evolution: Comparative population genetics in sandy beach crustaceans

Studies comparing the distribution of genetic diversity may help revealing connectivity patterns in marine populations, as they allow identifying factors behind genetic population structure and elucidating the relationship between the habitat and resident species. The macrofauna of sandy beaches constitutes an interesting study subject, since it includes species with contrasting life histories and dispersal strategies, with potential implications on connectivity. In this work, COI sequences of three peracaridan species with direct development (the talitrid amphipod Atlantorchestoidea brasiliensis and the cirolanid isopods Excirolana braziliensis and Excirolana armata), and one decapod with planktonic larvae (the hippid mole crab Emerita brasiliensis), were compared in order to evaluate the influence of dispersal and historical processes in the distribution of their genetic diversity in the Uruguayan coast, covering both marine and estuarine beaches located along the Rio de la Plata. The hypothesis that species with similar life histories show similar geographic patterns of genetic diversity did not completely explain the genetic variability observed in these species. The intertidal Emerita brasiliensis and the supralittoral Excirolana braziliensis presented high genetic homogeneity, with evidence of population expansion originated at similar times. This shared pattern of genetic variability could be explained by their tropical origin and recent colonization of the Uruguayan coast. The intertidal Excirolana armata and the supralittoral Atlantorchestoidea brasiliensis presented high variability, although differences between them could be associated with the beach zone they inhabit. The role of salinity affecting connectivity patterns was important in Excirolana armata and Atlantorchestoidea brasiliensis, which showed genetic differentiation between estuarine and oceanic beaches. Results reinforce the concept that the distribution of genetic variability not always reflects contemporary population structure and that it is important to consider the evolutionary history of the species when studying connectivity in sandy beach populations. Finally, the accelerated rates of warming in the region could favor a demographic explosion of Emerita brasiliensis and Excirolana braziliensis, species with tropical affinities, which is coherent with the documented demographic history of both species.

Variation in helminth infection prevalence, abundance, and co-infection in an intermediate host across a large spatial scale

Parasites are often distributed heterogeneously across host populations, but the controls of this heterogeneity across regional scales often remain unclear. Here, we test the relative importance of natural and anthropogenic environmental factors and biological attributes of host populations on the large-scale variability in infection probability and parasite abundance. We quantified a larval acanthocephalan parasite (Profilicollis altmani), as well as the trematodeMaritremasp. and the nematodeProleptussp., infection of mole crabsEmerita analogausing a hierarchical design at 8 sites spanning 500 km of the south-central shoreline of Chile. At each site, we measured the variables of beach size, morphodynamics, distance to nearest port, distance to tributaries, mole crab density, seagull density, and host body size. Using mixed-effects models, we analysed the associations of acanthocephalan infection probability and parasite abundance in mole crabs as functions of body size and the environmental site-level factors. Models accounted for 20 and 61% of variation in acanthocephalan infection probability and abundance, respectively, with mole crab body size exclusively accounting for nearly all of the model fits. Also, acanthocephalan abundance decreased with increasing mole crab density, suggesting a possible encounter-dilution effect. Co-infection was strong, with the 2 other larval parasite species correlated positively with acanthocephalan parasites. The low influence of environmental variables on acanthocephalan infection could be because spatial variability in these factors is relatively low or their influences are quick to saturate. Therefore, in this system, parasite infection is apparently more strongly related to the duration of host exposure than spatially variable environmental factors, even across large spatial scales.

Diversity of hippoidean crabs - considering ontogeny, quantifiable morphology, and phenotypic plasticity

Representatives of Hippoidea, often called sand crabs or mole crabs, are an ingroup of Anomala. These marine crustaceans inhabit the tropical and subtropical coasts of the world, yet some also appear in temperate climates. Their adults are specialized for digging and living in sandy substrates. Hippoidean zoea-type larvae are planktic and reach large sizes up to a few centimetres. These larvae transform into megalopa larvae, strongly resembling the adult, mediating the transition to the benthic lifestyle of the adult. We reconstructed outlines in dorsal view of over 80 shields of hippoideans, including representatives of Blepharipodidae (sister group to all others), Albuneidae, and Hippidae and including adults, megalopa-type, and zoea-type larvae from all three ingroups. We conducted a morphological analysis on this data using an elliptic Fourier transformation and principal component analysis. We used the results of the analysis to discuss the life history of hippoideans and the special function of megalopae, which often lack emphasis in current research. Early stage zoea larvae, megalopae, and adults show a linear gradient in their morphological development according to our analysis. However, late stage zoea larvae deviate from this pattern, possibly due to their specialization to a long-lasting planktic life. Lastly, we discuss the influence of phenotypic plasticity in hippoidean zoea larvae.

Habitat Preference and Abundance of Mole Crab Based on Sea Tides in Coastal Area of Kebumen Regency

Mole crab is an important resource in the food chain cycle and an initial level consumers in sandy areas. Mole crab lives in the swash zone that is affected by sea tides. Comparison of habitat and abundance of each station based on tides in terms of the type of utilization of the study location. The purpose of this study was to determine the abundance at high tide and low tide, species, and habitat preferences of mole crab, also to determine the relationship between their habitat preferences and their abundance. The method used in this study was descriptive exploratory and uses purposive random sampling technique. Abundance data collection was done by using a 10 x 10meter transect quadrant at two spring tides and two neap tides in the swash zone area. The results showed that the abundance of mole crab at high tide was 214 - 239 ind/100m2 and at low tide was 378 - 509 ind/100m2. There are three types of mole crab that has been found, Emerita emeritus, Hippa adactyla and Albunea symmysta. Favored habitat of mole crab in coast area of Kebumen Regency has a flat to sloping beach, wide swash zone at high tide 14.5 - 24.5m, and at low tide is 20 - 32.5m, medium sized beach sand (0.25-0.5mm), and has low organic material values. The results of the PCA (Principal Component Analysis) analysis that the sediment grain size and the width of the swash zone have a positive correlation with the abundance of mole crab.

Molecular Barcoding Reveals Possible Existence of Sympatric Species of Emerita emeritus in South Coast of Cilacap Central Java

Cilacap Regency resides in the southern part of Central Java. It faces the Indian Ocean and has a quite long coastline with sandy beaches as the favorable habitats for mole crabs. Careful examinations on previously identified as Emerita emeritus samples from Cilacap, the mole crabs showed slight morphological differences to Emerita emeritus Linnaeus. We assume that our samples are sympatric species of E. emeritus complex rather than E. emeritus Boyko. A length of 560 bp fragments of the cytochrome oxidase 1 was sequenced. Homology test resulted in 83 - 86% sequences similarity to E. emeritus sequence available in GenBank (KR047035). Our samples also had high genetic distances (0.152 -0.155) to the sequence of KR047035. The phylogenetic tree showed a clear separation between our samples and reference sequence (Emerita emeritus KR047035) with a quite long branch. Those all three kinds of data prove that our Emerita samples are most likely not belong to previously identified Emerita emeritus Boyko although it shows only slight morphological differences. These results indicate that possible cryptic species of Emerita emeritus or E. emeritus complex inhabits sandy beaches in Cilacap coast. It has been described that cryptic species are common in aquatic organisms. However, we need more samples to examine and strengthen our finding.

Assessment of larval connectivity in a sandy beach mole crab through a coupled bio-oceanographic model

The biophysical mechanisms influencing larval distribution and their impacts on the metapopulation dynamics of sandy beaches, particularly the connectivity patterns associated with larval dispersal, are poorly understood. Here, we identify larval connectivity patterns of the mole crab Emerita brasiliensis in the coast of Uruguay. A biophysical individual based model (IBM) of larval transport was coupled to a regional high-resolution physical model to estimate the monthly and interannual variation of larval connectivity, as well as the impact of the length of the reproductive period on it. Larval connectivity showed marked interannual variations, which were mainly related to interannual changes in seasonal winds and associated ocean circulation patterns, particularly during La Niña years. The southernmost area where E. brasiliensis occurs only received larvae from the nearest release area in November and January spawning events during a strong La Niña year, characterized by intense northeasterly winds. The Uruguayan coast constitutes the leading (poleward) edge of the distribution of E. brasiliensis, where climate change effects are projected to intensify. Extrapolation of these results to a climate change scenario with stronger La Niña events, suggest that larval transport to southernmost beaches will become more probable.

Infections by the trematode Microphallus nicolli and the acanthocephalan Profilicollis altmani in relation to the reproductive condition of their intermediate host, the Pacific mole crab Emerita analoga

Abstract Parasites can dramatically influence fecundity of their hosts, so for any host species it is important to establish whether parasite infections affect host reproduction. The Pacific mole crab, Emerita analoga, commonly harbors metacercarial cysts of the trematode Microphallus nicolli and cystacanths of the acanthocephalan Profilicollis altmani. Although these helminths are known to infect primarily larger female mole crabs, they may do so disproportionately when tied to their host’s reproductive condition. This study was undertaken to examine differences in parasite prevalence and abundance between non-ovigerous and ovigerous hosts. Crabs from Del Monte Beach, Monterey, California were collected, carapace length measured, sexed, examined for parasites, and had their reproductive state noted. The vast majority of the crabs sampled were infected with at least one parasite, and over half of the crabs had both M. nicolli and P. altmani. Ovigerous females were significantly larger than non-ovigerous crabs. Prevalence of both trematode metacercarial cysts and acanthocephalan cystacanths was significantly higher in ovigerous females than in non-ovigerous ones. Egg-bearing females were also more heavily infected by both parasites than non-egg-bearing individuals. These results suggest that larger ovigerous crabs may provide greater resources and thus are able to support higher levels of infections. This study shows that neither parasite prevalence nor abundance seemed to affect egg production in E. analoga.

New Records of Sand Crabs (Crustacea: Decapoda: Albuneidae and Blepharipodidae) from the Western Pacific with Description of Two New Species of Paralbunea Serène, 1977.

Two new species belonging to the sand crab genus Paralbunea Serène, 1977 are described: one each from the Philippines and Taiwan. Both new species can be distinguished from each other, as well as the five other species of Paralbunea, by characters of the carapace, eyes, and pereopods. Additional new western Pacific locality records are given for two species of spiny sand crabs (Blepharipodidae) and six species of sand crabs (Albuneidae). A key to all seven species of Paralbunea is provided.