Displaying publications 1 - 20 of 119 in total

Abstract:
Sort:
  1. On the identity of the poorly known pea crab, Pinnothera obesa Dana, 1852, and description of a new species of Arcotheres Manning, 1993 from the Southwest Pacific (Decapoda: Brachyura: Pinnotheridae)
    Komai T, Kawai K, Ng PKL
    Zootaxa, 2020 Aug 05;4822(2):zootaxa.4822.2.5.
    PMID: 33056290 DOI: 10.11646/zootaxa.4822.2.5
    The pinnotherid crab, Pinnothera obesa Dana, 1852, was originally described on the basis of material from Fiji, but its taxonomic status has long been obscure because the original description and figures are too brief and schematic by modern standards and the types are also lost. Examination of newly collected material from Fiji revealed the presence of two intertidal pinnotherid species assignable to the genus Arcotheres Manning, 1993, one of which is herein identified with Dana's taxon. A neotype is designated for Arcotheres obesus n. comb. in the interest of nomenclatural stability, and a detailed redescription is given. Arcotheres obesus is morphologically similar to A. exiguus (Bürger, 1895) and A. rotundatus (Bürger, 1895), and differentiating characters are discussed. The species is also reported from Peninsular Malaysia. The second species is new to science, here described as Arcotheres ocularius, and is most similar to A. palaensis (Bürger, 1895) and A. arcophilus (Bürger, 1895). The new species is also recorded from Lombok, Indonesia. Arcotheres obesus and A. ocularius n. sp. are associated with bivalve mollusks of the genera Gafrarium spp. (Veneridae) and Anadara spp. (Arcidae), respectively.
    Matched MeSH terms: Brachyura*
  2. A new species of highland vampire crab (Crustacea: Brachyura: Sesarmidae: Geosesarma) from Serian, Sarawak
    Ng PKL, Grinang J
    Zootaxa, 2018 Nov 02;4508(4):569-575.
    PMID: 30485965 DOI: 10.11646/zootaxa.4508.4.5
    A new species of semiterrestrial highland vampire crab of the family Sesarmidae, Geosesarma larsi n. sp., is described from western Sarawak. This brings the number of Bornean Geosesarma species to 12. Geosesarma larsi n. sp. is distinguished from congeners by the structures of the carapace, third maxilliped exopod and gonopods, as well as the proportions of its ambulatory legs. The colour pattern in life is also strikingly different from allied species. Notes on its ecology are provided and conservation threats briefly discussed.
    Matched MeSH terms: Brachyura*
  3. Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs
    Asmat-Ullah M, Rozaimi R, Fazhan H, Shu-Chien AC, Wang Y, Waiho K
    J Vis Exp, 2023 Mar 31.
    PMID: 37067269 DOI: 10.3791/65039
    Mud crabs (Scylla spp.) are commercially important crustacean species that can be found throughout the Indo-West Pacific region. During culture, the induction of ovarian maturation is important to meet the consumer demand for mature mud crabs and hasten seed production. Eyestalk ablation is an effective tool to enhance ovarian maturation in mud crabs. However, there is no standard protocol for the eyestalk ablation of mud crabs. In this study, two eyestalk ablation techniques are described: cauterization (the use of hot metal to ablate the eyestalk of an anesthetized crab) and surgery (the removal of the eyestalk using surgical scissors). Before eyestalk ablation, sexually mature females (CW > 86 mm) were anesthetized using an ice bag (-20 °C) with seawater. When the water temperature reached 4 °C, the ice bag was removed from the water. Flowing seawater (ambient temperature: 28 °C) was used for recovery from the anesthesia immediately after eyestalk ablation. Mortality did not occur during or after the process of eyestalk ablation. The eyestalk ablation protocol presented here accelerated the ovarian maturation of the mud crabs.
    Matched MeSH terms: Brachyura*
  4. The Brachyura described by Thomas Roscoe Rede Stebbing and a listing of Stebbing's South African Crustacea for the Marine Investigations in South Africa (Crustacea: Decapoda)
    Low ME, Ng PK
    Zootaxa, 2013;3599:371-6.
    PMID: 24613958 DOI: 10.11646/zootaxa.3599.4.5
    Matched MeSH terms: Brachyura/classification*
  5. New species of pinnotherid crabs from Southeast Asia and Papua New Guinea (Crustacea: Decapoda: Brachyura)
    Ahyong ST, Ng PKL
    Zootaxa, 2020 Jul 17;4816(3):zootaxa.4816.3.4.
    PMID: 33055692 DOI: 10.11646/zootaxa.4816.3.4
    Three new Indo-West Pacific species of pinnotherid crabs are described, one each of Arcotheres, Buergeres and Nepinnotheres. Arcotheres pollus, described from Paway Island, Mergui Archipelago, is most similar to A. boninensis (Stimpson, 1858), A. pernicola (Bürger, 1895) and A. purpureus (Alcock, 1900), sharing a transversely ovate carapace and long, slender, almost styliform dactyli of P4 and 5 that are about twice the length of those of P2 and 3. Buergeres choprai, described from Papua New Guinea, is most similar to B. deccanesis (Chopra, 1931) from eastern India but differentiated by segment proportions and setation of the walking legs. Buergeres tenuipes (Bürger, 1895) is synonymised with B. ortmanni (Bürger, 1895), which is also reported for the first time from Indonesia. A male of an undetermined species of Buergeres from the Philippines, possibly B. ortmanni, is figured and described, documenting the gonopod morphology in Buergeres for the first time. A key to the species of Buergeres based on females is provided. Nepinnotheres fulvia sp. nov. is also described from Papua New Guinea, and resembles N. cardii (Bürger, 1895) from the Philippines and Malaysia but can be distinguished by features of the chelipeds and maxilliped 3.
    Matched MeSH terms: Brachyura*
  6. Thermal tolerance and locomotor activity of blue swimmer crab Portunus pelagicus instar reared at different temperatures
    Azra MN, Chen JC, Ikhwanuddin M, Abol-Munafi AB
    J Therm Biol, 2018 May;74:234-240.
    PMID: 29801633 DOI: 10.1016/j.jtherbio.2018.04.002
    Owing to its potential market value, the blue swimmer crab Portunus pelagicus is of great economic importance. The temperature of water significantly affects the physiological function and production efficiency of these crabs. The aim of the present study was therefore to examine the critical thermal minimum (CTMin), critical thermal maximum (CTMax), acclimation response ratio (ARR), escaping temperature (Tesc), and locomotor behavior of P. pelagicus instars at 20 °C, 24 °C, 28 °C, 32 °C, and 36 °C. The CTMax ranged from 39.05 °C to 44.38 °C, while the CTMin ranged from 13.05 °C to 19.30 °C, and both increased directly with temperature. The ARR ranged from 0.25 to 0.51. The movement of crabs (walking before molting) correlated positively with the acclimation temperature. These results indicate that the parameters evaluated varied with temperature. Furthermore, the high CTMax indicates the potential of this species to adapt to a wide range of temperatures. In addition, the implications of these findings for portunid crabs behavior and distribution in their natural habitat are also discussed.
    Matched MeSH terms: Brachyura/physiology*
  7. On two new species of arboreal crabs from phytotelms in Sarawak, Borneo (Crustacea: Brachyura: Gecarcinucidae: Arachnothelphusa)
    Ng PKL
    Zootaxa, 2021 Aug 06;5016(3):407-418.
    PMID: 34810440 DOI: 10.11646/zootaxa.5016.3.6
    Two new species of the gecarcinucid freshwater crab genus Arachnothelphusa are described from the Malaysian state of Sarawak in Borneo; one from Lanjak-Entimau Wildlife Sanctuary and another from Bako National Park. Arachnothelphusa rimba n. sp. is distinctive in possessing very long legs and a male first gonopod which has a cylindrical proximal part of the terminal segment, with the distal part sharply tapering to an acute tip. Arachnothelphusa bako n. sp. is superficially closest to A. kadamaiana from Sabah, but differs markedly by its narrower epistome, and proportionately shorter third maxillipeds and ambulatory legs.
    Matched MeSH terms: Brachyura*
  8. Lepidothelphusa menneri n. sp. (Crustacea: Brachyura: Gecarcinucidae), first record of the genus from Kalimantan, Indonesia
    Ng PKL, Wowor D
    Zootaxa, 2024 Jan 04;5397(2):218-224.
    PMID: 38221209 DOI: 10.11646/zootaxa.5397.2.3
    The gecarcinucid freshwater crab genus, Lepidothelphusa Colosi, 1920, is known only from Sarawak in northern Borneo, with six recognised species i.e. Lepidothelphusa cognettii (Nobili, 1903); L. flavochela Grinang & Ng, 2015; L. limau Grinang & Ng, 2015; L. loi Grinang & Ng, 2015; L. padawan Grinang & Ng, 2015; and L. sangon Grinang & Ng, 2015. The genus is now reported from Indonesian Borneo for the first time, from specimens recently collected from Gunung Kelam in Sintang Regency, Kalimantan Barat Province. Lepidothelphusa menneri n. sp. has a very distinctive tri-coloured pattern in life, unique among congeners. It can also easily be separated from congeners by carapace, epistome, male pleonal and male first gonopod characters.
    Matched MeSH terms: Brachyura*
  9. A new species of troglobitic crab of the genus Stygothelphusa Ng, 1989, from Sarawak, Malaysia (Crustacea: Decapoda: Brachyura: Gecarcinucidae)
    Ng PK, Grinang J
    Zootaxa, 2014;3774:90-6.
    PMID: 24871408 DOI: 10.11646/zootaxa.3774.1.7
    A new species of cave crab, Stygothelphusa antu new species, is described from limestone formations in Temurang, Sarawak, Malaysia. The new species is the most highly adapted to a cavericolous lifestyle among the four known species of Stygothelphusa, having a pale body pigmentation, reduced eyes and elongated pereopods. In contrast, the other three species have normal eyes that almost completely fill the orbits. The new species also differs from its congeners by a number of carapace, pereopod and gonopod characters.
    Matched MeSH terms: Brachyura/anatomy & histology*; Brachyura/classification*
  10. The identity of the Sarawak freshwater crab Parathelphusa oxygona Nobili, 1901, with description of a new species, Parathelphusa nobilii, from Western Kalimantan, Indonesia, Borneo (Crustacea: Brachyura: Gecarcinucidae)
    Ng PK
    Zootaxa, 2014;3774:31-44.
    PMID: 24871403 DOI: 10.11646/zootaxa.3774.1.2
    The identity of the common lowland freshwater crab in western Sarawak, Borneo, East Malaysia, Parathelphusa oxygona Nobili, 1901 (family Gecarcinucidae), is clarified. The species is redescribed and figured, and its taxonomy discussed. Specimens from western Kalimantan, Borneo, Indonesia, which have been referred to P. oxygona are here referred to a new species, Parathelphusa nobilii. The new species can be differentiated from congeners by its relatively more swollen branchial regions of the carapace, wider and lower external orbital tooth, relatively more slender male abdomen and a straight male first gonopod. 
    Matched MeSH terms: Brachyura/anatomy & histology*; Brachyura/classification*
  11. Notes on Hexapodidae (Crustacea, Brachyura) from Indonesia and Malaysia, with description of a new species of Mariaplax Rahayu & Ng, 2014, from Lombok, Indonesia
    Ng PK, Rahayu DL
    Zootaxa, 2015 Jul 02;3981(1):125-37.
    PMID: 26249983 DOI: 10.11646/zootaxa.3981.1.7
    The male of Hexapinus latipes (De Haan, 1835), so far known only from female specimens, is described based on the material reported by De Man (1888) as "Hexapus sexpes". Material referred to "Hexapus sexpes" by Tesch (1918) is shown instead to belong to Hexapinus simplex Rahayu & Ng, 2014, and Hexapinus latus Rahayu & Ng, 2014, while his "Hexaplax megalops Doflein, 1904" belongs to Hexaplax aurantium Rahayu & Ng, 2014. A new species, Mariaplax aspera n. sp., is described from a female collected in Lombok, Indonesia. This new species most closely resembles M. narusei Rahayu & Ng, 2014, described from Japan, but differs by its relatively narrower carapace, shorter ambulatory legs, tuberculated third maxillipeds, and shorter telson.
    Matched MeSH terms: Brachyura/anatomy & histology*; Brachyura/classification*
  12. Fulltext Determination of key environmental factors responsible for distribution patterns of fiddler crabs in a tropical mangrove ecosystem
    Mokhtari M, Ghaffar MA, Usup G, Cob ZC
    PLoS One, 2015;10(1):e0117467.
    PMID: 25629519 DOI: 10.1371/journal.pone.0117467
    In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites within the mudflats of Sepang-Lukut mangrove forest. Temperature, porewater salinity, organic matter, water content, carbon and nitrogen content, porosity, chlorophyll content, pH, redox potential, sediment texture and heavy metals were determined in each 1 m2 quadrate. Pearson correlation indicated that all sediment properties except pH and redox potential were correlated with sediment grain size. Canonical correspondence analysis (CCA) indicated that Uca paradussumieri was negatively correlated with salinity and redox potential. Sand dwelling species, Uca perplexa and Uca annulipes, were highly dependent on the abundance of 250 μm and 150 μm grain size particles in the sediment. Canonical Discriminative Analysis (CDA) indicated that variation in sediment grain size best explained where each crab species was most abundant. Moreover, U. paradussumieri commonly occupies muddy substrates of low shore, while U. forcipata lives under the shade of mangrove trees. U. annulipes and U. perplexa with the high number of spoon tipped setae on their second maxiliped are specialized to feed on the sandy sediments. U. rosea and U. triangularis are more common on muddy sediment with high sediment density. In conclusion, sediment grain size that influences most sediment properties acts as a main factor responsible for sediment heterogeneity. In this paper, the correlation between fiddler crab species and environmental parameters, as well as the interaction between sediment characteristics, was explained in order to define the important environmental factors in fiddler crab distributions.
    Matched MeSH terms: Brachyura*
  13. Fulltext Heterochely and handedness in the orange mud crab Scylla olivacea: implication for future culture practice optimisation
    Rozaimi R, Shu-Chien AC, Wang Y, Sutikno S, Ikhwanuddin M, Shi X, et al.
    PeerJ, 2023;11:e15143.
    PMID: 37033733 DOI: 10.7717/peerj.15143
    Asymmetric body traits in bilateral organisms are common and serve a range of different functions. In crustaceans, specifically among brachyuran crabs, heterochely and handedness in some species are known to aid in behavioural responses such as food acquisition, and sexual and territorial displays. However, the heterochely of the intertidal mud crab genus Scylla is still poorly understood. This study investigated the cheliped morphometric characteristics of orange mud crab Scylla olivacea and the relation of heterochely and handedness to sex. Scylla olivacea is heterochelous, with predominant right-handed (70.2%). Three morphometric variables, i.e., propodus length (PL), propodus depth (PD), and propodus width (PW) were significantly larger in the right cheliped and the estimated handedness based on these three variables were consistent with the presence of molariform teeth. The effect of sex had no influence on the occurrence of heterochely or handedness. The frequency of left-handedness increased with size, especially in males. We postulate that handedness reversal, a phenomenon seen in other crab species when the dominant hand is lost, also occurs in S. olivacea, thereby resulting in a change in left-handedness frequency. The use of chelipeds by males in mate and territorial defenses might provide an explanation for the higher risk of losing a dominant cheliped and thus, higher left-handedness frequency compared to females. Future behavioural research could shed light on the selective forces that affect the handedness distribution in mud crabs. Knowledge on heterochely and handedness of mud crabs could be useful for future development of less aggressive crab populations by claw reversal and the optimisation of limb autotomy techniques.
    Matched MeSH terms: Brachyura*
  14. Upcycling crab shell waste into biochar for treatment of palm oil mill effluent via microwave pyrolysis and activation
    Yang Y, Foong SY, He Y, Liew RK, Ma NL, Yek PNY, et al.
    Environ Res, 2024 May 01;248:118282.
    PMID: 38295974 DOI: 10.1016/j.envres.2024.118282
    The escalating consumer demand for crabs results in a growing amount of waste, including shells, claws, and other non-edible parts. The resulting crab shell waste (CSW) is disposed of via incineration or landfills which causes environmental pollution. CSW represents a potential biological resource that can be transformed into valuable resources via pyrolysis technique. In this study, microwave pyrolysis of CSW using self-purging, vacuum, and steam activation techniques was examined to determine the biochar production yield and its performance in treating palm oil mill effluent (POME). The biochar produced through microwave pyrolysis exhibits yields ranging from 50 to 61 wt%, showing a hard texture, low volatile matter content (≤34.1 wt%), and high fixed carbon content (≥58.3 wt%). The KOH-activated biochar demonstrated a surface area of up to 177 m2/g that is predominantly composed of mesopores, providing a good amount of adsorption sites for use as adsorbent. The biochar activated with steam removed 8.3 mg/g of BOD and 42 mg/g of COD from POME. The results demonstrate that microwave pyrolysis of CSW is a promising technology to produce high-quality biochar as an adsorbent for POME treatment.
    Matched MeSH terms: Brachyura*
  15. Gonadal transcriptomic analysis of the mud crab Scylla olivacea infected with rhizocephalan parasite Sacculina beauforti
    Waiho K, Fazhan H, Zhang Y, Afiqah-Aleng N, Moh JHZ, Ikhwanuddin M, et al.
    Genomics, 2020 09;112(5):2959-2969.
    PMID: 32437851 DOI: 10.1016/j.ygeno.2020.05.007
    Infection by the rhizocephalan parasite Sacculina beauforti can have detrimental effects on mud crab Scylla olivacea. However, the molecular changes that occur during rhizocephalan infection are poorly understood. Due to the disruption in the reproductive system after infection, the gonadal transcriptomic profiles of non-infected and infected Scylla olivacea were compared. A total of 686 and 843 unigenes were differentially expressed between non-infected and infected males, and females, respectively. The number of DEGs increased after infection. By comparing shared DEGs of non-infected and infected individuals, potential immune- and reproduction-related of host, and immune- and metabolism-related genes of parasite are highlighted. The only shared KEGG pathway between non-infected and infected individuals was the ribosome pathway. In summary, findings in this study provide new insights into the host-parasite relationship of rhizocephalan parasites and their crustacean hosts.
    Matched MeSH terms: Brachyura/genetics*; Brachyura/immunology; Brachyura/metabolism; Brachyura/parasitology*
  16. Two reads to rule them all: Nanopore long read-guided assembly of the iconic Christmas Island red crab, Gecarcoidea natalis (Pocock, 1888), mitochondrial genome and the challenges of AT-rich mitogenomes
    Gan HM, Linton SM, Austin CM
    Mar Genomics, 2019 Jun;45:64-71.
    PMID: 30928201 DOI: 10.1016/j.margen.2019.02.002
    Despite recent advances in sequencing technology, a complete mitogenome assembly is still unavailable for the gecarcinid land crabs that include the iconic Christmas Island red crab (Gecarcoidea natalis) which is known for its high population density, annual mass breeding migration and ecological significance in maintaining rainforest structure. Using sequences generated from Nanopore and Illumina platforms, we assembled the complete mitogenome for G. natalis, the first for the genus and only second for the family Gecarcinidae. Nine Nanopore long reads representing 0.15% of the sequencing output from an overnight MinION Nanopore run were aligned to the mitogenome. Two of them were >10 kb and combined are sufficient to span the entire G. natalis mitogenome. The use of Illumina genome skimming data only resulted in a fragmented assembly that can be attributed to low to zero sequencing coverage in multiple high AT-regions including the mitochondrial protein-coding genes (NAD4 and NAD5), 16S ribosomal rRNA and non-coding control region. Supplementing the mitogenome assembly with previously acquired transcriptome dataset containing high abundance of mitochondrial transcripts improved mitogenome sequence coverage and assembly reliability. We then inferred the phylogeny of the Eubrachyura using Maximum Likelihood and Bayesian approaches, confirming the phylogenetic placement of G. natalis within the family Gecarcinidae based on whole mitogenome alignment. Given the substantial impact of AT-content on mitogenome assembly and the value of complete mitogenomes in phylogenetic and comparative studies, we recommend that future mitogenome sequencing projects consider generating a modest amount of Nanopore long reads to facilitate the closing of problematic and fragmented mitogenome assemblies.
    Matched MeSH terms: Brachyura/classification; Brachyura/genetics*
  17. Two Elongases, Elovl4 and Elovl6, Fulfill the Elongation Routes of the LC-PUFA Biosynthesis Pathway in the Orange Mud Crab (Scylla olivacea)
    Ting SY, Janaranjani M, Merosha P, Sam KK, Wong SC, Goh PT, et al.
    J Agric Food Chem, 2020 Apr 08;68(14):4116-4130.
    PMID: 32186869 DOI: 10.1021/acs.jafc.9b06692
    While the capacity for long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis has been elucidated in vertebrates and several invertebrate phyla, the comparative knowledge in crustaceans remains vague. A key obstacle in mapping the full spectrum of LC-PUFA biosynthesis in crustacean is the limited evidence of the functional activities of enzymes involved in desaturation or elongation of polyunsaturated fatty acid substrates. In this present study, we report on the cloning and functional characterization of two Elovl elongases from the orange mud crab, Scylla olivacea. Sequence and phylogenetic analysis suggest these two Elovl as putative Elovl4 and Elovl6, respectively. Using the recombinant expression system in Saccharomyces cerevisiae, we demonstrate the elongation capacity for C18-C22 PUFA substrates in the S. olivacea Elovl4. The S. olivacea Elovl6 elongated saturated fatty acids, monounsaturated fatty acids, and interestingly, C18-C20 PUFA. Taken together, both Elovl fulfill the elongation steps required for conversion of C18 PUFA to their respective LC-PUFA products. Elovl4 is expressed mainly in the hepatopancreas and gill tissues, while Elovl6 is predominant in digestive tissues. The mRNA expression of both enzymes was higher in mud crabs fed with vegetable oil-based diets. Tissue fatty acid composition also showed the existence of LC-PUFA biosynthesis intermediate products in tissues expressing these two elongases. In summary, we report here two novel Elovl with PUFA elongating activities in a marine brachyuran. This will contribute significantly to the understanding of the LC-PUFA biosynthesis pathway in crustaceans and advance the development of aquafeed for intensive farming of the mud crab.
    Matched MeSH terms: Brachyura/enzymology*; Brachyura/genetics
  18. Lipofuscin Level in Eyestalk Blue Swimming Crab, Portunus pelagicus at Different Sexes
    Ghani Hilmi M, Ikhwanuddin M
    Pak J Biol Sci, 2020 Jan;23(5):708-714.
    PMID: 32363828 DOI: 10.3923/pjbs.2020.708.714
    BACKGROUND AND OBJECTIVE: The accumulation of lipofuscin (LF) is an alternative technique to identify age of crustacean species. However, the exact sites and the level of the LF concentration were unknown especially for different sexes of blue swimming crab, Portunus pelagicus. Thus, the present study was aimed to identify which part of the eyestalk of P. pelagicus contains more LF levels in order to establish a specific target part of samples.

    MATERIALS AND METHODS: Thus, crab samples for this study were sampled from the wild habitat at Setiu wetlands, Terengganu, Malaysia. A total of 100 samples of with the same size (80±5 mm carapace width) were sampled and the eyestalk dissected for LF extraction. The determination of LF sites and levels in the eyestalks organ was taken from the area between the distal tangential layer (DTL) and proximal tangential layer (PTL). The lower part of the eyestalk was taken from the PTL until the end of the eyestalk.

    RESULTS: The upper part of the crab's eyestalk was higher in the males crabs compared to the females crabs. LF index also shown that the upper part of crab's eyestalk have higher concentration compared to the lower part.

    CONCLUSION: The left crab's eyestalk had the higher LF index especially in males compared to females but the total concentration was higher in female crabs. Knowing which part has highly dense accumulation of LF helps in LF detection of the tissue and further helps for age determination for this species.

    Matched MeSH terms: Brachyura/growth & development; Brachyura/metabolism*
  19. Fecundity, embryonic and ovarian development of blue swimming crab, Portunus pelagicus (Linnaeus, 1758) in coastal water of Johor, Malaysia
    Ikhwanuddin M, Azra MN, Siti-Aimuni H, Abol-Munafi AB
    Pak J Biol Sci, 2012 Aug 01;15(15):720-8.
    PMID: 24171257
    Blue swimming crab, Portunus pelagicus is widely study and research throughout the Indo-West Pacific, but little is known of its reproductive biology in Malaysia. The present study describes the fecundity, embryonic development and ovarian development stages of the P. pelagicus from Johor coastal water, Malaysia. Carapace width range of berried crabs sampled was from 9.64 to 13.32 cm, while the body weight range was from 75 to 235 g. The mean number of egg produced by females in different sizes ranged from 105443.333 +/- 35448.075 per eggs batch. Mean egg size during embryonic development at stage 1 was 0.307 +/- 0.037, while 0.386 +/- 0.039 and 0.396 +/- 0.033 for stage 2 and stage 3, respectively. Study showed that there was significant (p < 0.05) relationship between the number of eggs and carapace width/body weight. Mean diameter oocyte during ovarian development at stage 1 was 97.732 +/- 12.391 while for stage 2 was 149.516 +/- 23.287. Stage 3 showed increasingly of size with mean diameter was 158.506 +/- 27.616 and 181.013 +/- 24.339 for stage 4.
    Matched MeSH terms: Brachyura/embryology*; Brachyura/physiology*
  20. Bioaccumulation of heavy metals, antioxidants, and metabolic enzymes in the crab Scylla serrata from different regions of Tuticorin, Southeast Coast of India
    Yogeshwaran A, Gayathiri K, Muralisankar T, Gayathri V, Monica JI, Rajaram R, et al.
    Mar Pollut Bull, 2020 Sep;158:111443.
    PMID: 32753221 DOI: 10.1016/j.marpolbul.2020.111443
    The present study was performed to analyze the bioaccumulation of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes in the crab Scylla serrata from different regions of Tuticorin, Southeast Coast of India. The study area consists of Threspuram and Harbour Beach which were polluted environments due to the discharge of industrial effluents and domestic sewage into them. Punnakayal, which is a low-polluted environment where the in-situ culture of S. serrata is carried out by local fish farmers, was selected as well. The results revealed that the level of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes were significantly high in the crabs collected from Threspuram and Harbour Beach compared to the crabs collected from Punnakayal. This study indicates that crabs from polluted environments have significant heavy metals bioaccumulation which leads to elevated antioxidants and metabolic enzyme levels. This implies that the crabs are under oxidative and metabolic stress.
    Matched MeSH terms: Brachyura*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links