1
|
Cui W, Fang S, Lv L, Huang Z, Lin F, Wu Q, Zheng H, Li S, Zhang Y, Ikhwanuddin M, Ma H. Evidence of Sex Differentiation Based on Morphological Traits During the Early Development Stage of Mud Crab Scylla paramamosain. Front Vet Sci 2021; 8:712942. [PMID: 34395579 PMCID: PMC8358326 DOI: 10.3389/fvets.2021.712942] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 06/21/2021] [Indexed: 11/21/2022] Open
Abstract
In order to uncover the sexual difference in morphology and how early they appear during the development stage of mud crab Scylla paramamosain, we measured, observed, and biostatistically analyzed morphological traits related to sex. For unveiling the morphological differences between sexes, morphological traits involving abdomen width (AW), carapace length (CL), and carapace width (CW) were first measured during the crablet development stage of S. paramamosain in the present study. The correlation analyses and path analyses exhibited that sexual dimorphism in the third abdomen width (AW3) and fourth abdomen width (AW4) could be used for sex identification from stage C VI (stage VI of crablet). Based on the stepwise discriminant analysis and standardized traits, a sex discriminant equation was constructed, which is capable for sex identification in crablets from stage C VI. Observations for secondary sexual traits and abdomen morphology (shape and pleopods) using a dissecting microscope or scanning electron microscope indicated that sexes are easily identified at stage C VIII according to the abdomen shape; meanwhile, at stage C II based on pleopod difference, and at stage C I by the presence or absence of gonopores. The findings in this study contribute greatly to the accuracy of sex identification of S. paramamosain during the early development stage, which promotes the understanding of the morphological differentiation mechanism of sex.
Collapse
Affiliation(s)
- Wenxiao Cui
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Shaobin Fang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Ligang Lv
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Zhi Huang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Fei Lin
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Qingyang Wu
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Huaiping Zheng
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Shengkang Li
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Yueling Zhang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Mhd Ikhwanuddin
- Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China.,Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Hongyu Ma
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China.,Shantou University- Universiti Malaysia Terengganu, Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| |
Collapse
|
2
|
Fazhan H, Waiho K, Fujaya Y, Rukminasari N, Ma H, Ikhwanuddin M. Sexual dimorphism in mud crabs: a tale of three sympatric Scylla species. PeerJ 2021; 9:e10936. [PMID: 33954025 PMCID: PMC8048398 DOI: 10.7717/peerj.10936] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 01/21/2021] [Indexed: 11/20/2022] Open
Abstract
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).
Collapse
Affiliation(s)
- Hanafiah Fazhan
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia.,STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, China.,Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China
| | - Khor Waiho
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia.,STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| | - Yushinta Fujaya
- Faculty of Marine Science and Fishery, Hasanuddin University, Makassar, Indonesia
| | - Nita Rukminasari
- Faculty of Marine Science and Fishery, Hasanuddin University, Makassar, Indonesia
| | - Hongyu Ma
- STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, China.,Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China
| | - Mhd Ikhwanuddin
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia.,STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, China
| |
Collapse
|
3
|
Grinang J, Das I, Ng PKL. Geometric morphometric analysis in female freshwater crabs of Sarawak (Borneo) permits addressing taxonomy-related problems. PeerJ 2019; 7:e6205. [PMID: 30783559 PMCID: PMC6378089 DOI: 10.7717/peerj.6205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 12/03/2018] [Indexed: 11/20/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- Jongkar Grinang
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia
| | - Indraneil Das
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia
| | - Peter K L Ng
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore, Singapore
| |
Collapse
|