Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp

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...

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Main Authors: Hanafiah Fazhan, Khor Waiho, Emilia Quinitio, Juliana C. Baylon, Yushinta Fujaya, Nita Rukminasari, Mohammad Farhan Darin Azri, Md. Sheriff Shahreza, Hongyu Ma, Mhd Ikhwanuddin
Format: Article
Language:English
Published: PeerJ Inc. 2020-01-01
Series:PeerJ
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Online Access:https://peerj.com/articles/8066.pdf
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author Hanafiah Fazhan
Khor Waiho
Emilia Quinitio
Juliana C. Baylon
Yushinta Fujaya
Nita Rukminasari
Mohammad Farhan Darin Azri
Md. Sheriff Shahreza
Hongyu Ma
Mhd Ikhwanuddin
author_facet Hanafiah Fazhan
Khor Waiho
Emilia Quinitio
Juliana C. Baylon
Yushinta Fujaya
Nita Rukminasari
Mohammad Farhan Darin Azri
Md. Sheriff Shahreza
Hongyu Ma
Mhd Ikhwanuddin
author_sort Hanafiah Fazhan
collection DOAJ
description 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.
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spelling doaj.art-be12575a64da4b7ab19ec543c02ab68d2023-12-03T09:55:29ZengPeerJ Inc.PeerJ2167-83592020-01-018e806610.7717/peerj.8066Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla sppHanafiah Fazhan0Khor Waiho1Emilia Quinitio2Juliana C. Baylon3Yushinta Fujaya4Nita Rukminasari5Mohammad Farhan Darin Azri6Md. Sheriff Shahreza7Hongyu Ma8Mhd Ikhwanuddin9Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong, ChinaGuangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong, ChinaAquaculture Department, Southeast Asian Fisheries Development Center, Iloilo, PhilippinesDivision of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, Ioilo, PhilippinesFaculty of Marine Science and Fishery, Hasanuddin University, Makassar, IndonesiaFaculty of Marine Science and Fishery, Hasanuddin University, Makassar, IndonesiaFaculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, MalaysiaInstitute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Terengganu, Terengganu, MalaysiaGuangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong, ChinaSTU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, Guangdong, ChinaThere 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.https://peerj.com/articles/8066.pdfScyllaDiscriminant Function AnalysisMorphometricPresumed HybridsMud Crab
spellingShingle Hanafiah Fazhan
Khor Waiho
Emilia Quinitio
Juliana C. Baylon
Yushinta Fujaya
Nita Rukminasari
Mohammad Farhan Darin Azri
Md. Sheriff Shahreza
Hongyu Ma
Mhd Ikhwanuddin
Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp
PeerJ
Scylla
Discriminant Function Analysis
Morphometric
Presumed Hybrids
Mud Crab
title Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp
title_full Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp
title_fullStr Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp
title_full_unstemmed Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp
title_short Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp
title_sort morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of scylla spp
topic Scylla
Discriminant Function Analysis
Morphometric
Presumed Hybrids
Mud Crab
url https://peerj.com/articles/8066.pdf
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