Sand Crab Research Articles

Acanthocephalan Profilicollis altmani infecting the mole crab Emerita brasiliensis in southeastern Brazil

Acanthocephalan parasites, specifically from the genus Profilicollis, are known to infect decapod crustaceans, including mole crabs like Emerita brasiliensis, which serve as intermediate hosts in their complex life cycles. This study reports the first occurrence of the acanthocephalan parasite Profilicollis altmani infecting the mole crab Emerita brasiliensis on a sandy beach in southeastern Brazil, thereby expanding the known geographic range of this parasite. Additionally, the study provides novel molecular data that enhance our understanding of the parasite’s taxonomy and distribution, including the first evidence of genetic variation within populations of the intermediate host E. brasiliensis. Phylogenetic analysis based on mitochondrial COX1 gene sequences confirmed the identification of the parasite and underlined small genetic differences among P. altmani populations. These findings suggest a weak genetic population structure of the parasite and underscore the need for further studies to understand gene flow among these populations. This work contributes to the knowledge of parasite-host interactions in sandy beach ecosystems. It highlights the importance of monitoring parasitic infections in species like E. brasiliensis, which play a crucial ecological role in these environments.

Sex-specific differences in the growth and population characteristics of Sand crab Ovalipes punctatus (De Haan, 1833) in coastal waters of Korea

The sex-specific differences in the growth and population characteristics of the high-commercial-value sand crab Ovalipes punctatus were investigated in Korea. The estimated allometric growth between the sexes showed significant differences in all morphometric measurements. In the classification of growth types, carapace width-chela length exhibited positive and negative allometric growth in males and females, respectively. Carapace width-abdominal width showed positive relative growth in both sexes, and orbital spine width exhibited negative relative growth in both sexes. Consequently, sexual dimorphism was evident in all measured traits. Growth parameters estimated using the ELEFAN function of the FiSAT II program indicated higher values in males compared to females. Asymptotic length (CW∞) for males was estimated at 139.2 mm, whereas for females it was 116.6 mm. Additionally, the growth coefficient (K) was higher in males (0.65) than in females (0.54), suggesting faster growth in males. The winter point (WP) was 1 for males and 0.7 for females, indicating slower growth in males during the colder December and slower growth in females during the spawning period in August. The modified von Bertalanffy growth curves indicated asymptotic growth in all sexes, and the growth performance index (φ') showed higher values in males (4.10) compared to females (3.87), reflecting differences in growth curves. The steady increase in recruitment rates from July to September was associated with the appearance of larvae and their subsequent growth into juveniles, leading to their recruitment into the population during this period. Therefore, O. punctatus exhibited sex-specific differences in growth parameters, suggesting distinct growth strategies between the sexes.

Reproductive ecology of the sand crab (Ovalipes punctatus) population in the Yellow Sea of Korea

AbstractUnderstanding the reproductive ecology of crustaceans is important for developing appropriate resource management policies. Because the demand for sand crabs (Ovalipes punctatus) as a food resource has recently surged in Korea, their reproductive ecological characteristics should be comprehensively described. In this study, the reproductive ecological characteristics—sex ratio, female gonad maturity, abdominal width (AW), condition factor (K), and gonadosomatic index (GSI)—of individuals of O. punctatus collected from the Yellow Sea in Korea (35°15′00″N, 125°15′00″E) from January to December 2021 were examined. Based on the sex ratio (1:1.61, females:males), we determined that males were more abundant than females. The monthly K for both the males and females reached its maximum in April. The monthly GSI revealed that the males were most numerous in December, whereas the females were most abundant in May. The GSI graph indicates that the main spawning season of O. punctatus is from May to July. The AW and GSI of the females increased as their gonads matured; based on this correlation, the maturity of female individuals can be determined by examining the abdominal flap morphology. The results of histological analysis indicated that females of O. punctatus exhibit synchronous development, by which oocytes develop simultaneously. Furthermore, the size at maturity, at which more than half of the individuals participated in spawning, was 75.6 mm. The findings of this study contribute to the development of policies for the sustainable fisheries of O. punctatus.

Assessing the ecological impact of beach tourism on crustacean abundance: a case study from West Coast of India

Sandy beaches are vulnerable to natural and anthropogenic disturbances like coastal hydrological disasters, coastal erosion, sea-level rise, pollution, and land degradation. Apart from these, at the habitat level, tourism and recreation activities impact the sandy beach ecosystem in countless ways. Several studies indicate that trampling caused due to human visitation negatively impacts the macrobenthic communities. In this study, along with the trampling effect, we assessed the impact of human visitation on the sandy beach ecosystem using factors like littering and human-induced predation pressure. The study was conducted on three sandy beaches in the Udupi district of Indian coastal state, Karnataka. We used human presence, predation pressure, and total litter as response variables; against sand crabs and ghost crabs as indicator species. The results indicated a significant correlation between response variables. Sand crabs were less affected by the human presence (r = 0.07, p = 0.14); however, ghost crab abundance was negatively influenced by human presence (r = − 0.36, p < 0.05), predation pressure (r = − 0.28, p < 0.05), and by litter presence (r = − 0.28, p < 0.05) at the beaches. We observed that human presence impacts sand crabs and ghost crabs directly (trampling) and indirectly (attracting human commensal predators through beach litter). We highlight the impacts of tourism on often neglected crab assemblages and emphasise the importance of deriving appropriate conservation measures for sandy beach ecosystems.

Risk analysis of crab peeling business: a case study at miniplant Medan I Deli Serdang

Abstract Portunus pelagicus also known as also known as the blue crab, blue swimmer crab, blue manna crab or sand crab is a species of large crab found in the Indo-Pacific, including off the coasts of Indonesia. The crab peeling industry represents an attractive business opportunity in the seafood sector, with growing demand for processed crab meat. Miniplant Medan I is a business located in north Sumatra which specializing in crab peeling to obtain quality crab meat. However, like any business venture, it is not without its inherent risks. This study aims to identify, assess, and evaluate potential risks, uncertainties, and hazards that can affect the crab peeling business Miniplant Medan I. Risk measurement in this study is carried out using the PIM (Probability Impact Matrix) method. The result shows that the highest risk factors in the Miniplant Medan I business are overexploitation of crab’s eggs and small sizes crab, employee negligence in the use of prohibited cosmetic ingredients, use of low-quality raw materials, cold chain disconnection, lack of employee and equipment sanitation.

Genetic Diversity and Differentiation of Sand Crab (Albunea symmysta) (Crustacea: Decapoda: Hippoidea) from Java and Papua, Indonesia

In Indonesia, the sand crab Albunea symmysta distribution includes Java, Sumatra, and Moluccas. Populations are assumed to be differentiated between western and eastern Indonesia due to the Wallace line; however, no information on the genetic diversity and differentiation of A. symmysta in Indonesia is available. This study was conducted to clarify the genetic diversity and differentiation of A. symmysta in Indonesia. During the sampling campaign, A. symmysta specimens were found only in Java and Papua. Genetic analysis based on the 643-bp fragment of the partial COI gene from 32 individuals revealed significant genetic differentiation between the Java and Papua populations (FST = 0.94, p &lt; 0.005). The haplotype connectivity of the five A. symmysta sampling sites revealed a two-clade network. Based on analysis of molecular variance, most of the variation was found among populations (94.21%) rather than within populations (5.79%). Tajima's D and Fu's FS values indicated a population expansion. Overall, the findings support a high level of differentiation between the Java and Papua A. symmysta populations, suggesting the separation of population stocks due to low connectivity.

Genetic differentiation of Hippa adactyla based on CO1 gene sequence in Sundaland

The Hippidae is a family of sand crabs that inhabit intertidal ecosystems, specifically in sandy areas scattered throughout the coast. Differences in habitat conditions cause variations in Hippidae members. Hippa adactyla is a member of the genus Hippa. This study aimed to map the genetic differentiation between Hippa adactyla populations in the Greater Sunda Islands. The sand crab (Hippa adactyla) samples were taken from Sumatra (Pariaman, Bengkulu, Lampung) and Java (Pangandaran, Pelabuhan Ratu, Banyuwangi) by handcatching then stored in alcohol 96%. Total genomic DNA was extracted from the muscle tissue of the samples using a commercial DNA Extraction KIT. The upper part of the COI gene (5' end) (±750 bp) was amplified using specific primers. Based on the K2P substitution model, the genetic distance of the Pangandaran population to the Bali Strait population is the same as that of the Sumatran population (0.062). Genetic diversity ranges from 0.000 to 0.123. Haplotype diversity was 0.928, consisting of 18 haplotypes.

SAND CRAB (Emerita sp.) MEAL AS A NOVEL FEED INGREDIENT FOR KOI CARP (Cyprinus carpio)

Sand crab (Emerita sp.) is a marine biodiversity, but it has not been used as a fish feed ingredient. This study aimed to evaluate the nutritional value of sand crabs and to understand its effect when used as feed ingredient on the performance of Koi carp. The study was conducted in two steps, which is evaluation of the nutritional value of sand crab and its effect on fish performance. The proximate composition, amino acids, and fatty acids were measured using AOAC methods, and then the carotenoid content was determined by spectrophotometry. In the second step, the sand crab was added to fish feed at doses of 0, 5, 10, and 15 percent, and fed to koi fish for 42 days. The parameters observed were length gain (LG), weight gain (WG), and feed efficiency (FE). Nutritional data were analyzed by description and compared with fish feed ingredients from previous studies. Fish performance were analyzed by one-way ANOVA. When significant, Tukey’s significant mean test was applied. The result showed that the nutritional value of sand crab was comparable to other feed ingredients with a protein content of 37.88%, while carotenoid content was superior. The best performance of Koi carp was obtained with a dose of 15% sand crab in the diet, with LG, WG, and FE values of 0.93 ± 0.05 cm, 0.48 ± 0.06 g, and 63.50 ± 7.05 %, respectively. Based on this result, it can be concluded that sand crab has a high nutritional value and can be used up to 15% in Koi carp diet.

New distribution record of Hippoid crabs on Bali strait, Indonesia

Hippoidea are known as sand crabs or mole crabs. The distribution of these crabs in Indonesia is found in the Sundaland and the eastern region bounded by the Wallacea line. The purpose of this study was to determine the existence of Hippoidea’s species in Bali Strait. The crab collection was carried out in the Bali Strait during 2 weeks in May 2023. The collection of mole crab in Bomo and Blimbingsari beaches, Banyuwangi and Watu Ulo Beach Regency East Java. Sample collection was done in the morning between 6:00-10:00 am using hands pickup and fishing bait. All of the crab samples that were successfully collected were documented on the beach sand as a photo background, then preserved in 96%. Based on the morphological identification, there were 2 species of mole crab, namely Hippa adactyla (n=11) individuals, and Albunea symysta (4) individuals. The species found on the Blimbingsari beach was only H. adactyla (5). The species from Watu Ulo Beach were 2 species Hippa adactyla (n=8) individuals, and Albunea symysta (1) individuals. These results show a new distribution and record in the central part of Indonesia, especially at the boundary of the Wallacea line.

ANALISIS PROKSIMAT KEPITING PASIR (Ocypode Cursor) SEBAGAI SUMBER MAKANAN BERGIZI BAGI MASYARAKAT PESISIR DI KECAMATAN SALAHUTU PULAU AMBON

Background: The use of the Ocypode Cursor sand crab as a source of nutritious food for coastal communities in the Salahutu District area is because this marine animal is found living in sandy substrates along the coast and can be used as a source of nutritious food for coastal communities. Methods: Water content measurement was carried out using the oven method. Determination of ash content is carried out using the dry ashing method. Determination of fat content was carried out using the Soxhlet method. Analysis of protein levels using the Kjeldahl micro method. Results: The results of proximate analysis of sand crab for 100 grams of meat showed a water content of 79.72%, ash content of 6.82%, fat content of 7.5%, protein content of 15.7%. Conclusion: The results of the analysis show that there is a significant regression according to the regression provisions y = a + bx= 3,266 + 0.016, and the value of R2 = 0.802, even the analysis also shows that there is a significant influence according to the value of df = 24-22 = 2 with the value of F = 44,588 with a significance level of 000, &lt; p 0.05, this means that there is a significant influence between the availability of the Ocypode cursor sand crab population in its habitat and Ocypode cursor as a source of nutritious food for the community (OcMGz).

Evidence using morphology, molecules, and biogeography clarifies the taxonomic status of mole crabs of the genus Emerita Scopoli, 1777 (Anomura, Hippidae) and reveals a new species from the western Atlantic.

Uncertainties regarding the taxonomic status and biogeographical distribution of some species of the genus Emerita from the western Atlantic led to thorough examination of the subtle morphological differences between two coexistent species (E.brasiliensis Schmitt, 1935 and E.portoricensis Schmitt, 1935) along the Brazilian coast and compare them using two genetic markers. The molecular phylogenetic analysis based on sequences of the 16S rRNA and COI genes showed that individuals identified as E.portoricensis were clustered into two clades: one containing representatives from the Brazilian coast and another containing specimens distributed in Central America. Our molecular-based phylogeny, combined with a detailed morphological analysis, revealed the Brazilian population as a new species, which is described here as Emeritaalmeidai Mantelatto & Balbino, sp. nov. The number of species in the genus Emerita is now raised to 12, with five of them occurring in the western Atlantic, five in the Indo-Pacific, and two in the eastern Pacific.

β-Carotene Analysis and Histological Investigation on Different Egg Stages of Anomuran Crab, Emerita Asiatica (H. Milne Edwards, 1837)

Histological investigation and β-carotene analysis of different egg stages of anomuran crab, Emerita asiatica was studied. This investigation characterized the morphological and histological features of the ovaries; eggs and also resulted in the identification of the following structures such as Previtellogenic Oocyte, Vitellogenic Oocytes, Atretic Oocyte, matured Oocyte and its associated structures which are quiet common structures that are found in almost every Sand Crab. This study can be further used in studying the reproductive biology of this Sand Crab (Emerita asiatica). It can also be used in determining the structural and morphological changes that can happen in gonads due to the action of various microorganisms such as bacteria, viruses and fungi by artificial infections. The observation described in this study will serve as a reference for future research aimed at studies based on environmental factors, temperature, climatic conditions, and feeding that might have an effect on this species. The conversion of β-carotene into vitamin A (retinol), for clear eyesight and healthy eyes, a robust immune system, and healthy skin and mucous membranes, we require vitamin A. Large amounts of vitamin A can be hazardous, but our bodies only make as much of the vitamin from β-carotene as is required. The sand crab serves as a different source of β-carotene than vitamin A, even though E. asiatica is not widely used. Though E. asiatica is not a commercially viable crab, it plays a vital role in the environment to maintain a stable marine ecosystem. Several steps and preventive measures should be taken to conserve these members of the marine food chain to have a stable ecosystem and also to protect this species from extinction. Further, this study can potentially benefit as baseline information for the future research on the species.

The importance of feeding fast when thieves are around: A case study on Whimbrels foraging on a wave‐exposed sandy beach in southern Chile

AbstractPrey profitability is one of the most important factors influencing prey selection. This factor varies along with both prey size and handling time. Thus, large prey are generally highly profitable for consumers and boost competition. Kleptoparasitism is a form of competition in which an individual steals food previously obtained by another individual. Accordingly, handling large prey should increase the likelihood of kleptoparasitism occurrence, but these relationships remain poorly understood. Here, we studied kleptoparasitism occurrence by the Brown‐Hooded Gull (Chroicocephalus maculipennis – Laridae) on Whimbrels (Numenius phaeopus hudsonicus – Scolopacidae) preying on intertidal Mole Crabs (Emerita analoga) in a wave‐exposed sandy beach in southern Chile. Generalized linear models, fitted to data from focal‐individual video sequences, showed that kleptoparasitism probability had a positive sigmoidal response to handling time. Moreover, with an increase of 1 s in handling time, a Whimbrel doubled its probability of being kleptoparasitized. Additionally, the odds of being kleptoparasitized were 17% higher with an increase of 10 mm in prey length and 47% higher with an increase of one gull per host. However, the effect of handling on kleptoparasitism probability slightly decreased (2%) with an increase of 10 mm in prey size class. Our results suggest the existence of a threshold time in which consumers can handle their prey before kleptoparasitism probability is too high. Nevertheless, Whimbrel's mean intake rate reached 0.15 ± 0.13 kJ s−1, allowing Whimbrels to theoretically meet their energetic requirements despite losing some prey to kleptoparasites. This study provides new insight into a common form of competition among consumers, highlighting the importance of prey handling time for shorebirds with a restricted foraging time driven by tidal cycles.

Redescription of the mole crab Emerita portoricensis Schmitt, 1935 (Crustacea: Decapoda: Hippidae), based on Caribbean populations from Puerto Rico, Belize, Costa Rica, and Panama

The mole crab Emerita portoricensis Schmitt, 1935 was originally described solely on the basis of few key characters that were not precisely defined, giving reason to question subsequent reports of its distribution. The present study, prompted by recent collections documenting coloration in life, undertakes a comprehensive redescription of the species based on specimens of varied sizes from Puerto Rico, Belize, Costa Rica, and Panama. Collections from the northern Caribbean that at first take appear to represent a northernmost record of E. brasiliensis Schmitt, 1935 or southernmost occurrence of E. talpoida (Say, 1817), may be assignable E. portoricensis as now recognized. Among western Atlantic species, E. portoricensis and E. benedicti have to date been considered to have the dactylus of the first pereopod terminally subacute or sharply pointed, which purportedly separates them from E. brasiliensis and E. talpoida, western Atlantic species in which this article is terminally rounded. However, in E. portoricensis this character varies with specimen size and the magnification at which the distal extreme of the dactylus is examined, being rounded to varying degrees in all but the largest specimens. Even in sexually mature specimens of less than maximum size, this rounded tip is armed by a minute corneous spine in E. portoricensis, although it is less prominent than the terminal spine on the consistently more acute dactylus of E. benedicti at all adult sizes. Also, the carapace color in live specimens of E. portoricensis, as documented for specimens collected in both Belize and Panama, differs from that of E. brasiliensis, E. talpoida, and E. benedicti by typically including longitudinal and diagonal dark bars of olive brown on the branchial regions and a light longitudinal bar marking the posterior quarter of the median line. Posterior to the cervical groove, fine rugae of the carapace that form broken transverse lines are at most little diminished across the mid-dorsal longitudinal line in E. portoricensis and E. benedicti, somewhat more broken in E. brasiliensis, and distinctly diminished to all but absent at the midline in E. talpoida. Previously reported BINs in the Barcode of Life database include sequenced specimens from Costa Rica herein accepted as E. portoricensis. We exclude populations from Brazil that have been mis-assigned to E. portoricensis.

Effect of Different Enriched Crickets (Gryllus sigilatus) on Growth and Pigmentation of Asian Arowana (Scleropages formosus) Var. Super Red

This study aimed to evaluate the effect of crickets enriched with a source of carotenoids on fish’s growth, colour, and total carotenoid content in juvenile Asian Arowana (Scleropages formosus). Six juveniles were fed with different enriched crickets (G. sigilatus) based on the following treatments: (A) Crickets fed with fish feed without enrichment, (B) Crickets fed with fish feed containing 500 ppm of synthetic astaxanthin, and (C) Crickets fed with a combination of 50% fish feed, 48% sand crab meal and 2% marigold petal meal. The results of the study revealed that The weight gain (WG), specific growth rate (SGR), feed efficiency (FE), length gain (LG), and survival rate (SR) for treatment A were 110 g, 1.16% head/day, 45.79%, 10.98 cm, and 100% respectively. There was also no significant difference (P&gt;0.05) with the other treatments. However, treatment B had a positive effect on the redness (a*) of the Arowana tail with a value of 9.52, and treatment C increased the yellowness (b*) of the Arowana body with a value of 2.77 (P&lt;0.05), which was different to the other treatments. There were no differences between any of the treatments concerning the effects on lightness (L*), chromaticity (C*), and hue (H*) on either the body or the tail. The astaxanthin enrichment produced the highest carotenoid content (P&lt;0.05) with a value of 45.09 µg/g. Enriching crickets with astaxanthin influence colour and carotenoid content but not the growth of the Asian Arowana fish.

Potential long-term disturbance associated with beach nourishment - insights and observations from Pea Island National Wildlife Refuge, Outer Banks, North Carolina

The longer-term ecosystem impacts associated with a beach nourishment project conducted in 2014 were studied on an ocean beach on the Pea Island National Wildlife Refuge on North Carolina's Outer Banks. The unique nature of the project is tied to the study's duration, which spans nine years, and the venue, a national wildlife refuge where human-sourced confounding effects are minimal. Populations for five invertebrates: Emerita talpoida (the Atlantic Mole Crab), Donax variabilis (the Coquina Clam), Scolelepis squamata, Ocypode quadrata (the Atlantic Ghost Crab), and indigenous Amphipods were monitored seasonally over nine-years that asymmetrically straddled the 2014 nourishment event. Beach sediments were also monitored in concert with the biodata. Results show that the 2014 nourishment fill sands were finer than those native to the study area beach, however, reworking quickly brought the fill sands on the nourished beach into size parity with native sediments observed on a predefined control site.Findings from this investigation fail to present evidence to suggest that any type of ephemeral species die-off occurred in association with the 2014 nourishment event. While die-offs are commonplace reported, such outcomes are not inevitable. Other investigators have documented ecosystem resilience against significant disturbances such as beach nourishment—this study appears to corroborate such findings, both at the system and species levels. Many argue that nourishment fill sand characteristics: their fit to the native sediment in terms of size and composition, and their application during construction, are the principal determinants driving the disturbance response and subsequent post-nourishment recovery. This study corroborates this fill-sand/recovery relationship but provides evidence to support a causation argument only circumstantially.

Reappraisal of the status of two recently described western Atlantic species of sand crabs (Anomura: Albuneidae)

Reappraisal of the status of two recently described western Atlantic species of sand crabs (Anomura: Albuneidae)

Keanekaragaman Undur-Undur Laut (Anomura: Hippidae) Dari Kepulauan Banda

Mole crabs are part of the superfamily Hippoidea and members of the family Hippidae Latreille,1825, which inhabit sandy beaches, particularly the swash zone. This condition is commonly found in the Banda Islands. The purpose of this research was to determine the species diversity of the genus Hippa Fabricius, 1787 in the Banda Islands. We identified the species by its morphological characters. Sample collection was done by purposive sampling method. Based on the study's findings, four of the five previously reported species in Indonesia were identified. Hippa ovalis (A. Milne-Edwards, 1862), H. adaactyla Fabricius, 1787, H. marmorata (Hombron &amp; Jacquinot, 1846), and H. celaeno (De Man, 1896) were the species obtained. Hippa cf. ovalis and Hippa cf. marmorata are both presumed to be new species. This study includes descriptions of the two species.&#x0D; &#x0D; Keywords: distribution, Hippidae, Hippa, intertidal, sandy substrate

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

Acute toxicity of Chlorpyrifos on histological alterations in the different organs like gills, hepatopancreas and ovary of anomuran crab, Emerita asiatica was studied. Though Emerita asiatica is not a commercially viable crab, but it plays a vital role in the environment to maintain a stable marine ecosystem. Several steps and precautions measures should be taken to conserve these members of the marine food chain to have a stable ecosystem and also to protect this species from extinction. Thus, it can be concluded that the use of Chlorpyrifos 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 Chlorpyrifos causes serious damage to the vital organ of sand crabs gill, hepatopancreas and ovary. The application of Chlorpyrifos could be reduced in the agricultural field to nearby coastal regions.

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.