Displaying publications 1 - 20 of 36 in total

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  1. Antony P, Rahman M, Rajkumar M, Kamaruzzaman Yunus, Ajmal Khan S
    Sains Malaysiana, 2014;43:1305-1310.
    Morphometric analysis was carried out to find out changes in the growth pattern of male and female stomatopod, Harpiosquilla raphidea. Six morphometric relationships were examined on 105 males and 105 females, ranging in size from 103 to 207 mm and from 104 to 222 mm in total length, respectively. In both the sexes, the relative growth of carapace length, propodus length of raptorial claw and total weight in relation to total length was found positively allometric. Telson width in both the sexes and abdomen width in males showed slightly negative allometry, while the abdomen width of females showed slightly positive allometry, indicating some variation in the growth between sexes which could be attributed to the energy requirement for maturation in females. The propodus of females was also found to be bigger than that of males. It is quite interesting as males only have larger chela in other crustaceans. It has a functional significance in that it is of immense help at the time of intense feeding during maturation of oocytes which requires higher energy.
    Matched MeSH terms: Animal Shells
  2. Baki MA, Hossain MM, Akter J, Quraishi SB, Haque Shojib MF, Atique Ullah AKM, et al.
    Ecotoxicol Environ Saf, 2018 Sep 15;159:153-163.
    PMID: 29747150 DOI: 10.1016/j.ecoenv.2018.04.035
    A contaminated aquatic environment may end up in the food chain and pose risks to tourist health in a tourist destination. To assess the health risk for tourists that visit St. Martine Island, which is a popular domestic and foreign tourist destination in Bangladesh, a study is undertaken to analyse the level of heavy metal contamination from chromium (Cr), manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg) and iron (Fe) in six of the most consumed fish (L. fasciatus, R. kanagurta, H. nigrescens, P. cuneatus, P. annularis and S. rubrum) and five crustacean species, which consist of a shrimp (P. sculptilis), a lobster (P. versicolor) and three crabs (P. sanguinolentus, T. crenata and M. victor) captured. The samples were analysed for trace metals using atomic absorption spectrometer, and the concentrations of the metals were interpreted using the United State Environmental Protection Agency (USEPA) health risk model. The muscle and carapace/exoskeleton of shrimp, lobster and crabs were analysed and contained various concentrations of Pb, Hg, As, Cr, Cd, Fe, Cu, Zn and Mn. The hierarchy of the heavy metal in marine fish is Fe > Cd > Zn > Pb > Cu > Cr > Mn > Hg. The concentrations of Pb in the species R. kanagurta, H. nigresceus and S. rubrum were above the food safety guideline by Australia, New Zealand and other legislations in most marine fish and crustaceans. Crabs showed higher mean heavy metal concentrations than shrimp and lobster. Acceptable carcinogen ranges were observed in three fish species (R. kanagurata, H. nigresceus and S. rubrum) and one crustacean species (P. sculptilis) samples.
    Matched MeSH terms: Animal Shells/chemistry
  3. Chuah, Y.J., Tan, Y.P., Abdullah, H.A.
    MyJurnal
    The crab carapace is a waste which cannot be decomposed. This waste was used to
    remove the Reactive Orange 16 (RO16) and Basic Blue 3 (BB3) from aqueous solution
    at different operational parameters such as pH, mass load, the concentrations of dye and
    the temperature. The crab collected was modified to obtain quaternized crab (QC) using
    (3-chloro-2-hydroxypropyl) trimethylammonium chloride solution (C6H15Cl2NO, 65% w/w
    in water). The pH of the dyes solution was varied from pH 4 to 10. The highest adsorption
    percentage was achieved at pH 7 for both dyes. Increasing the QC mass for the adsorption
    process had granted an increase of dyes removal percentage. The highest adsorption
    percentage was achieved at 91.00% for RO16 and 29.40% for BB3 dyes with 7.5 g/L QC
    used. However, the adsorption capacity of QC decreased with higher QC mass because the
    dye molecules occupied on the surface and prevented other molecules to diffuse into the
    QC. At higher concentration beyond 20 mg/L and 10 mg/L of RO16 and BB3, respectively,
    the maximum adsorption was achieved at 2.5362 mg/g and 0.6812 mg/g. The adsorption of
    both dyes by QC was best fitted using Langmuir isotherm model, explaining the adsorption
    mainly occurred as a single layer on the surface of QC. Comparison to the results obtained
    from the kinetic models, the adsorption was
    chemisorption in nature. According to the
    thermodynamic studies, the adsorption of
    RO16 was an exothermic, while BB3 was
    an endorthermic process.
    Matched MeSH terms: Animal Shells
  4. Deeleman-Reinhold CL, Miller J, Floren A
    Zookeys, 2016.
    PMID: 26877691 DOI: 10.3897/zookeys.556.6174
    Depreissia is a little known genus comprising two hymenopteran-mimicking species, one found in Central Africa and one in the north of Borneo. The male of Depreissia decipiens is redescribed, the female is described for the first time. The carapace is elongated, dorsally flattened and rhombus-shaped, the rear of the thorax laterally depressed and transformed, with a pair of deep pits; the pedicel is almost as long as the abdomen. The male palp is unusual, characterized by the transverse deeply split membranous tegulum separating a ventral part which bears a sclerotized tegular apophysis and a large dagger-like retrodirected median apophysis. The female epigyne consists of one pair of large adjacent spermathecae and very long copulatory ducts arising posteriorly and rising laterally alongside the spermathecae continuing in several vertical and horizontal coils over the anterior surface. Relationships within the Salticidae are discussed and an affinity with the Cocalodinae is suggested. Arguments are provided for a hypothesis that Depreissia decipiens is not ant-mimicking as was previously believed, but is a mimic of polistinine wasps. The species was found in the canopy in the Kinabalu area only, in primary and old secondary rainforest at 200-700 m.a.s.l. Overlap of canopy-dwelling spider species with those in the understorey are discussed and examples of species richness and endemism in the canopy are highlighted. Canopy fogging is a very efficient method of collecting for most arthropods. The canopy fauna adds an extra dimension to the known biodiversity of the tropical rainforest. In southeast Asia, canopy research has been neglected, inhibiting evaluation of comparative results of this canopy project with that from other regions. More use of fogging as a collecting method would greatly improve insight into the actual species richness and species distribution in general.
    Matched MeSH terms: Animal Shells
  5. Fazhan H, Waiho K, Fujaya Y, Rukminasari N, Ma H, Ikhwanuddin M
    PeerJ, 2021;9:e10936.
    PMID: 33954025 DOI: 10.7717/peerj.10936
    Sexual dimorphism is a common phenomenon in the animal kingdom. To test the consistency of sexual dimorphism patterns among sympatric species of the same genus, ten morphometric characteristics of mud crabs Scylla olivacea, S. tranquebarica and S. paramamosain were measured and compared using Discriminant Function Analysis (DFA). The descriptive analysis revealed that in all three species, body size dimensions and cheliped dimensions were significantly larger in males whereas the abdomen width was female-biased. Also, we described a morphological variation (carapace width, CW ≤ CW at spine 8, 8CW) that is unique to S. olivacea. Discriminant function analysis revealed that all nine morphometric characteristics were sexually dimorphic in S. olivacea, S. tranquebarica (except right cheliped's merus length, ML) and S. paramamosain (except 8CW). The obtained discriminant functions based on the morphometric ratios (with CW as divisor) correctly classified 100% of adults of known sex of all three species. Further, based on the selected body traits, DFA was able to almost completely distinguish males (94%), but not females (74%), among the three Scylla species. This study highlights that congeneric species of portunids (e.g., Scylla spp.) show similar sexually dimorphic characteristics (body size and secondary sexual characteristics).
    Matched MeSH terms: Animal Shells
  6. Fazhan H, Waiho K, Quinitio E, Baylon JC, Fujaya Y, Rukminasari N, et al.
    PeerJ, 2020;8:e8066.
    PMID: 31915566 DOI: 10.7717/peerj.8066
    There are four species of mud crabs within the genus Scylla, and most of them live sympatrically in the equatorial region. Apart from a report in Japan about the finding of a natural Scylla hybrid more than a decade ago after the division of genus Scylla into four species by Keenan, Davie & Mann (1998), no subsequent sighting was found. Thus, this study investigates the possible natural occurrence of potential hybridization among Scylla species in the wild. A total of 76,211 individuals from mud crab landing sites around the Malacca Straits, South China Sea and Sulu Sea were screened. In addition to the four-purebred species, four groups (SH 1, n = 2, 627; SH 2, n = 136; SH 3, n = 1; SH 4, n = 2) with intermediate characteristics were found, mostly at Sulu Sea. Discriminant Function Analysis revealed that all Scylla species, including SH 1 - 4, are distinguishable via their morphometric ratios. The most powerful discriminant ratios for each character and the top five discriminant ratios of males and females were suggested. The carapace width of SH 1 males and females were significantly smaller than pure species. Based on the discriminant ratios and the description of morphological characters, we hypothesize that the additional four groups of Scylla with intermediate characteristics could be presumed hybrids. Future work at the molecular level is urgently needed to validate this postulate.
    Matched MeSH terms: Animal Shells
  7. Ghazali Azmie, Mohamad N. Azra, Mhd Ikhwanuddin, Siti Fatimah Nahar, Wendy Wee, Ambok-Bolong Abol-Munaf
    Sains Malaysiana, 2018;47:427-432.
    The aim of this study was to investigate how various diets influence testis maturation stages in mud crab (Scylla olivacea)
    broodstock. Morphological and histological assessments were performed in triplicate (10 male crabs each). Daily,
    subject crabs were fed a squid (Loligo sp.) and a fish (Decapterus sp.) diet at 5-10% of body weight. Diets were analyzed
    following methods from the Association of Analytical Communities (AOAC). In comparison to control (wild) crabs, the
    two diets generally did not cause significant differences (p>0.05) in body weight, carapace width and gonadosomatic
    index (GSI), except in the GSI of squid-fed crabs (p<0.05). At the end of the experiment, crabs that reached Stage 3 testis
    maturation included were 6 fish-fed individuals and 23 squid-fed individuals. Additionally, differences in crude protein
    and fat levels across diets influenced the nature of male gonadal development. In conclusion, a squid diet was sufficient
    to induce Stage 3 testis maturation in Scylla olivacea within 60 days of culture. Our results prove the usefulness in
    developing appropriate feeding regimes for male Scylla olivacea broodstock.
    Matched MeSH terms: Animal Shells
  8. Grinang J, Das I, Ng PKL
    PeerJ, 2019;7:e6205.
    PMID: 30783559 DOI: 10.7717/peerj.6205
    The taxonomy of freshwater crabs requires a paradigm change in methodological approaches, particularly in investigations that use morphological techniques. The traditional morphometric approach (two-dimensional measurements) tends to be inappropriate for the identification of freshwater crabs due to their variable external morphology and lack of gonopods (conventionally used for the identification of male crabs) in females. In this study, we explore the potential use of the geometric morphometric technique for identification of female freshwater crabs, and identify taxonomic key characteristics of species. The shape of the carapace could be a good characteristic for the identification of female crabs, especially when the geometric morphometric technique is used. It was observed that the shape of the carapace has an advantage over the shape of the pleon and chela because its relatively flat orientation allows more consistent and easier data preparation for geometric morphometric analysis. The geometric morphometric technique is inexpensive, relatively less time consuming to employ, and accurate. This technique is convenient when dissection to examine the gonopods is not possible, which can damage the specimen in the case of endangered or rare species. Since the technique was used herein for only two species, more compelling and extensive evidence is needed before the reliability of the method can be proven.
    Matched MeSH terms: Animal Shells
  9. Hamli H, Idris MH, Abu Hena MK, Rajaee AH, Arshad A
    J Environ Biol, 2016 07;37(4 Spec No):641-6.
    PMID: 28779722
    The morphology and 12 shell morphometric features proportionate to shell length were analysed between local hard clam; Meretrix lyrata, M. meretrix and M. lusoria from Sarawak, Malaysia. Meretrix spp. was observed to comprise a unique feature of a pallial sinus scar for each species. Analysis of variance revealed significant differences among Meretrix spp. using proportion ratios of SL for SW; LL; AL; LCT; AW; PW and PS (p<0.05). Cluster analysis among morphometric features of M. lyrata, M. meretrix and M. lusoria were discriminated at 98.5% similarities and supported by the principal component analysis. The present study suggests that pallial sinus scar shape, together with interior and exterior morphometric features, were suitable as identification keys for Meretrix spp. Hence, the present study emphasizes on the application of interior, rather than exterior morphology and morphometric features in hard clam identification before further investigation can be performed through genetic identification means.
    Matched MeSH terms: Animal Shells/anatomy & histology*
  10. Hammadi NI, Abba Y, Hezmee MNM, Razak ISA, Jaji AZ, Isa T, et al.
    Pharm Res, 2017 06;34(6):1193-1203.
    PMID: 28382563 DOI: 10.1007/s11095-017-2135-1
    PURPOSE: Here, we explored the formulation of a calcium carbonate nanoparticle delivery system aimed at enhancing docetaxel (DTX) release in breast cancer.

    METHODS: The designed nano- anticancer formulation was characterized thorough X-ray diffraction (XRD), Fourier transformed infrared (FTIR), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) and Brunauer-Emmett-Teller (BET) methods. The nano- anticancer formulation (DTX- CaCO3NP) was evaluated for drug delivery properties thorough in vitro release study in human body simulated solution at pH 7.4 and intracellular lysosomal pH 4.8.

    RESULTS: Characterization revealed the successful synthesis of DTX- CaCO3NP, which had a sustained release at pH 7.4. TEM showed uniformly distributed pleomorphic shaped pure aragonite particles. The highest entrapment efficiency (96%) and loading content (11.5%) were obtained at docetaxel to nanoparticles ratio of 1:4. The XRD patterns revealed strong crystallizations in all the nanoparticles formulation, while FTIR showed chemical interactions between the drug and nanoparticles with negligible positional shift in the peaks before and after DTX loading. BET analysis showed similar isotherms before and after DTX loading. The designed DTX- CaCO3NP had lower (p  0.05) effects at 48 h and 72 h. However, the DTX- CaCO3NP released less than 80% of bond DTX at 48 and 72 h but showed comparable effects with free DTX.

    CONCLUSIONS: The results showed that the developed DTX- CaCO3NP released DTX slower at pH 7.4 and had comparable cytotoxicity with free DTX at 48 and 72 h in MCF-7 cells.

    Matched MeSH terms: Animal Shells/chemistry
  11. Hasyima Ismail N, Amin Safwan A, Fairuz Fozi N, Megat FH, Muhd Farouk H, Kamaruddin SA, et al.
    Pak J Biol Sci, 2017;20(3):140-146.
    PMID: 29023005 DOI: 10.3923/pjbs.2017.140.146
    BACKGROUND: Orange mud crab Scylla olivacea is one of the most important fisheries resources. A new development in ageing technique of crustaceans has been introduced. The detection of growth band deposited in hard structure of gastric mill in the cardiac stomach are found retained after moulting process can be used as age indicator and growth estimation.

    OBJECTIVE: This study was carried out to determine the comparison between carapace width and growth band count of S. olivacea in Malaysia.

    MATERIALS AND METHODS: Samples were collected from Setiu Wetlands, Terengganu, Malaysia from February until August, 2016. Samples were categorized based on their morphological measurements. The mesocardiac and zygocardiac ossicles in the gastric mill of S. olivacea was dissected out and preserved in solutions and underwent a cross sectioning process. A total of 76 of wild S. olivacea ranging from 6.56 to 12.84 cm in carapace width were analysed. The growth band counts were examined for each individual and ranging from 1 to 3 band counts.

    RESULTS: A positive linear relation was observed between CW and GBC with r2 = 0.5178, p<0.01. Overall, there was a strong, positive correlation between CW and GBC. Increase in CW were correlated with increases in GBC respectively for this species.

    CONCLUSION: Therefore, the carapace width, growth band counts and body weight can be used to improve data on growth, recruitment, maturation and mortality. Thus, this study would able to improve new ageing technique and contribute greatly to improve the conservation and management of S. olivacea in Setiu Wetlands, Terengganu, Malaysia.

    Matched MeSH terms: Animal Shells/growth & development*
  12. Ibiyeye KM, Zuki ABZ
    Int J Mol Sci, 2020 Mar 10;21(5).
    PMID: 32164352 DOI: 10.3390/ijms21051900
    Cancer stem cells CSCs (tumour-initiating cells) are responsible for cancer metastasis and recurrence associated with resistance to conventional chemotherapy. This study generated MBA MD231 3D cancer stem cells enriched spheroids in serum-free conditions and evaluated the influence of combined doxorubicin/thymoquinone-loaded cockle-shell-derived aragonite calcium carbonate nanoparticles. Single loaded drugs and free drugs were also evaluated. WST assay, sphere forming assay, ALDH activity analysis, Surface marker of CD44 and CD24 expression, apoptosis with Annexin V-PI kit, cell cycle analysis, morphological changes using a phase contrast light microscope, scanning electron microscopy, invasion assay and migration assay were carried out; The combination therapy showed enhanced apoptosis, reduction in ALDH activity and expression of CD44 and CD24 surface maker, reduction in cellular migration and invasion, inhibition of 3D sphere formation when compared to the free drugs and the single drug-loaded nanoparticle. Scanning electron microscopy showed poor spheroid formation, cell membrane blebbing, presence of cell shrinkage, distortion in the spheroid architecture; and the results from this study showed that combined drug-loaded cockle-shell-derived aragonite calcium carbonate nanoparticles can efficiently destroy the breast CSCs compared to single drug-loaded nanoparticle and a simple mixture of doxorubicin and thymoquinone.
    Matched MeSH terms: Animal Shells/chemistry
  13. Ikhwanuddin M, Abol-Munafi AB, Azra MN
    Data Brief, 2019 Aug;25:104196.
    PMID: 31321277 DOI: 10.1016/j.dib.2019.104196
    This data article includes raw and analyze data for molting duration and time of hardening of blue swimming crab, Portunus pelagicus instar at three different temperatures of 24 °C, 28 °C, and 32 °C. Two sets of experimental data are included: first, the recorded on time-lapse video of duration of successful molted crabs (from emergence of swimming legs to chelae); and second, the time interval of shell hardening up to before molting occurred. Shell hardening were calculated in 1 h interval with a unit of x hour molting crab-1, meanwhile the molting duration of the crabs were calculated in x second molting crab-1. Video files were then analyzed using the latest version of Solomon Coder software developed by A. Peter. Relationship between culture temperature and the time of molting and carapace hardening are also included in this article. The dataset is made publicly available to enable critical or extended analyzes.
    Matched MeSH terms: Animal Shells
  14. Ikhwanuddin M, Amin-Safwan A, Hasyima-Ismail N, Azra MN
    Data Brief, 2019 Oct;26:104477.
    PMID: 31667242 DOI: 10.1016/j.dib.2019.104477
    The present paper contains two datasets; i) the growth band count (GBC) of mud crab, Scylla olivacea collected from Setiu Wetlands, Terengganu coastal water, East coast of Peninsular Malaysia and ii) the increment sizes of body weight (BW) and carapace width (CW) of immature S. olivace after molting. The datasets presented here were associated with the research articles entitled i) "Study on carapace width growth band counts relationship of orange mud crab, S. olivacea (Herbst, 1796) from Terengganu Coastal Waters, Malaysia" (Hasyima-Ismail et al. 2017) [1] and ii) "Relationship between the carapace width and body weight increments and the confirmation of Stage 1 ovary after the molting of immature orange mud crabs, S. olivacea (Herbst, 1796), in captivity" (Amin-Safwan et al. 2019-2020) [2], and provided here as raw data of Supplementary materials. Raw datasets for GBC in the wild were generated by examination of the thin cross sectioning process of the gastric mill of S. olivacea. The GBC were measured for each individual crab wherein band counts ranged from 1 to 3. The analysis provides evidence that the GBC of the crabs can be determined through both mesocardiac and zygocardiac ossicles. This data is of importance to researchers for estimation of stock assessment and improvement of fisheries management to further improve policy. For the BW-CW increment data, a total of 135 immature crabs were sampled from Setiu Wetlands, Terengganu, Malaysia, and were introduced to limb autotomy technique in order to induced molt. Crabs were reared until successful molting and immediately prior to hardened shell, before final measurement of body weight and carapace width determination. Recorded data was analyzed by calculating the increment sizes, along with correlation and regression analysis between body weight and carapace width of mud crabs.
    Matched MeSH terms: Animal Shells
  15. Irna C, Jaswir I, Othman R, Jimat DN
    J Diet Suppl, 2018 Nov 02;15(6):805-813.
    PMID: 29185824 DOI: 10.1080/19390211.2017.1387885
    Astaxanthin is one of the main carotenoid pigments. It has beneficial effects on the immune system of the human body due to its powerful antioxidant properties. The application of this bioactive compound can be found to be significant in the food, pharmaceutical, and cosmetics industries. The aim of this research was to investigate astaxanthin yield from six species of Malaysian shrimp carapace. Six types of shrimp species-Parapenaeopsis sculptili, Metapenaeus lysianassa, Macrobrachium rosenbergii, Metapenaeopsis hardwickii, Penaeus merguiensis, and Penaeus monodon-were used to investigate total carotenoid content and astaxanthin yield. The investigation was carried out using chemical extraction and high-pressure processing (HPP) methods at 210 MPa, for a period of 10 min with a solvent mixture of acetone and methanol (7:3, v/v). HPP was proven to have a significant impact in increasing the total carotenoid content and astaxanthin yield. The highest total carotenoid content and astaxanthin yield is shown to be contained in the Penaeus monodon species. Total carotenoid was increased from 46.95 µg/ml using chemical extraction to 68.26 µg/ml using HPP; yield of astaxanthin was increased from 29.44 µg/gdw using chemical extraction to 59.9744 µg/gdw using HPP. Therefore, comparison between the HPP and chemical extraction methods showed that HPP is more advantageous with higher astaxanthin yield, higher quality, and shorter extraction time.
    Matched MeSH terms: Animal Shells/chemistry*
  16. Ismail FA, Aris AZ, Latif PA
    Environ Sci Pollut Res Int, 2014 Jan;21(1):344-54.
    PMID: 23771443 DOI: 10.1007/s11356-013-1906-4
    This work presents the structural and adsorption properties of the CaCO3(-)-rich Corbicula fluminea shell as a natural and economic adsorbent to remove Cd ions from aqueous solutions under batch studies. Experiments were conducted with different contact times, various initial concentrations, initial solution pH and serial biosorbent dosage to examine the dynamic characterization of the adsorption and its influence on Cd uptake capacity. The characterization of the C. fluminea shell using SEM/EDX revealed that the adsorbent surface is mostly impregnated by small particles of potentially calcium salts. The dominant Cd adsorption mechanism is strongly pH and concentration dependent. A maximum Cd removal efficiency of 96.20% was obtained at pH 7 while the optimum adsorbent dosage was observed as 5 g/L. The Langmuir isotherm was discovered to be more suitable to represent the experimental equilibrium isotherm results with higher correlation coefficients (R(2) > 0.98) than Freundlich (R(2) 
    Matched MeSH terms: Animal Shells/chemistry*
  17. Jalil AA, Triwahyono S, Yaakob MR, Azmi ZZ, Sapawe N, Kamarudin NH, et al.
    Bioresour Technol, 2012 Sep;120:218-24.
    PMID: 22820110 DOI: 10.1016/j.biortech.2012.06.066
    In this work, two low-cost wastes, bivalve shell (BS) and Zea mays L. husk leaf (ZHL), were investigated to adsorb malachite green (MG) from aqueous solutions. The ZHL was treated with calcined BS to give the BS-ZHL, and its ability to adsorb MG was compared with untreated ZHL, calcined BS and Ca(OH)(2)-treated ZHL under several different conditions: pH (2-8), adsorbent dosage (0.25-2.5 g L(-1)), contact time (10-30 min), initial MG concentration (10-200 mg L(-1)) and temperature (303-323 K). The equilibrium studies indicated that the experimental data were in agreement with the Langmuir isotherm model. The use of 2.5 g L(-1) BS-ZHL resulted in the nearly complete removal of 200 mg L(-1) of MG with a maximum adsorption capacity of 81.5 mg g(-1) after 30 min of contact time at pH 6 and 323 K. The results indicated that the BS-ZHL can be used to effectively remove MG from aqueous media.
    Matched MeSH terms: Animal Shells/chemistry*
  18. Koch M, ĎuriŠ Z
    Zootaxa, 2018 Feb 27;4387(3):567-579.
    PMID: 29690481 DOI: 10.11646/zootaxa.4387.3.9
    A new species of the portunid genus, Monomia Gistel, 1848, is described from the South China Sea in Vietnam. Monomia lucida sp. nov. is morphologically most similar to M. argentata (A. Milne-Edwards, 1861), which was originally described from Sarawak, on the island of Borneo. In addition to the stout, forward-directed anterolateral teeth of the carapace, the subrectangular sixth segment of the male pleon, and the long and slender laterally bent first gonopods, adults of the new species reach a greater size, and can also be distinguished from M. argentata by the colour pattern on the natatory dactylus. The independent specific status of M. lucida sp. nov. is also supported by molecular evidence. Aside from a comparison of this new species with other known congeners, new photographs of the holotype of M. samoensis (Ward, 1939) are also provided.
    Matched MeSH terms: Animal Shells
  19. Li Y, Lin Y, Li S
    Zookeys, 2020;988:63-128.
    PMID: 33223891 DOI: 10.3897/zookeys.988.56188
    Crassignatha Wunderlich, 1995 is redefined to include species with six eyes in three diads, chelicerae fused only near the base, sculpturing on the carapace, one or two clasping spurs on tibia II, a bilateral scutum of the male abdomen, and globular spermathecae and adjacent copulatory openings in the female. A key and distribution map are provided for 24 Crassignatha species in this paper. Diagnoses and illustrated photographs are provided for 22 species from China, Malaysia, Thailand, and Vietnam. Thirteen species are described and documented as new to science: C. baihua Y. Lin & S. Li, sp. nov. (♂♀), C. bangbie Y. Lin & S. Li, sp. nov. (♀), C. changyan Y. Lin & S. Li, sp. nov. (♀), C. dongnai Y. Lin & S. Li, sp. nov. (♀), C. gucheng Y. Lin & S. Li, sp. nov. (♂♀), C. mengla Y. Lin & S. Li, sp. nov. (♂♀), C. nantou Y. Lin & S. Li, sp. nov. (♂♀), C. nasalis Y. Lin & S. Li, sp. nov. (♂♀), C. rostriformis Y. Lin & S. Li, sp. nov. (♂♀), C. shunani Y. Lin & S. Li, sp. nov. (♂♀), C. si Y. Lin & S. Li, sp. nov. (♂♀), C. thamphra Y. Lin & S. Li, sp. nov. (♀), and C. xichou Y. Lin & S. Li, sp. nov. (♀). Three new combinations are proposed: C. bicorniventris (Lin & Li, 2009), comb. nov., C. quadriventris (Lin & Li, 2009), comb. nov., and C. shiluensis (Lin & Li, 2009), comb. nov. are transferred from Patu Marples, 1951. DNA barcodes and genetic distances of seventeen species are obtained to confirm correct identification. Types of seven known Chinese Crassignatha species are re-examined, and the taxonomic placement of C. longtou Miller, Griswold & Yin, 2009 may be incorrect based on morphological and molecular data.
    Matched MeSH terms: Animal Shells
  20. Liew TS, Schilthuizen M
    PLoS One, 2016;11(6):e0157069.
    PMID: 27280463 DOI: 10.1371/journal.pone.0157069
    Quantitative analysis of organismal form is an important component for almost every branch of biology. Although generally considered an easily-measurable structure, the quantification of gastropod shell form is still a challenge because many shells lack homologous structures and have a spiral form that is difficult to capture with linear measurements. In view of this, we adopt the idea of theoretical modelling of shell form, in which the shell form is the product of aperture ontogeny profiles in terms of aperture growth trajectory that is quantified as curvature and torsion, and of aperture form that is represented by size and shape. We develop a workflow for the analysis of shell forms based on the aperture ontogeny profile, starting from the procedure of data preparation (retopologising the shell model), via data acquisition (calculation of aperture growth trajectory, aperture form and ontogeny axis), and data presentation (qualitative comparison between shell forms) and ending with data analysis (quantitative comparison between shell forms). We evaluate our methods on representative shells of the genera Opisthostoma and Plectostoma, which exhibit great variability in shell form. The outcome suggests that our method is a robust, reproducible, and versatile approach for the analysis of shell form. Finally, we propose several potential applications of our methods in functional morphology, theoretical modelling, taxonomy, and evolutionary biology.
    Matched MeSH terms: Animal Shells/anatomy & histology*
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