Zoological Studies

Vol. 51 No. 1, 2012

Molecular and Morphological Investigations of Shovel-Nosed Lobsters Thenus spp. (Crustacea: Decapoda: Scyllaridae) in Thailand

Apinan Iamsuwansuk1, Jessada Denduangboripant1,*, and Peter J.F. Davie2

1Department of Biology, Faculty of Science, Chulalongkorn Univ., Phayathai Road, Phatumwan, Bangkok 10330 Thailand
2Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101, Australia

Apinan Iamsuwansuk, Jessada Denduangboripant, and Peter J.F. Davie (2012) Shovel-nosed lobsters (Thenus spp.) (or kang-kradan in Thai) are the basis of an increasingly important fishery in Thailand and other tropical Indo-West Pacific countries. In the past, only a single species was recognized, Thenus orientalis. However, a recent taxonomic revision, using both morphological and DNA sequence analyses, established that at least 3 species occur in Thai waters. The present work was designed to test the results of that earlier study as applied to the Thai fishery, and extend it by using a broader sampling regime. Thirty adult Thenus specimens were sampled from 3 provinces: Chonburi (on the eastern Gulf of Thailand), Phetchaburi (on the western Gulf of Thailand), and Phuket (on the Andaman Sea). Genomic DNA was extracted from pereiopods, and the mitochondrial cytochrome c oxidase subunit 1 (COI) gene was amplified and sequenced. A 403-base pair nucleotide data matrix was used to derive phylogenetic trees using maximum parsimony. The molecular phylogeny clearly separated the Thai specimens into 3 clades: 13 individuals of T. indicus, 7 of T. orientalis, and 10 of T. unimaculatus. The recently proposed morphological criteria were largely effective in separating Thenus species; however some of the morphometric ratios given in the previous paper need to be adjusted. New local Thai names are proposed: kang-kradan thammada (common shovel-nosed lobster) for T. indicus, kang-kradan kha-lai (spotted-leg shovel-nosed lobster) for T. orientalis, and kang-kradan kha-muang (purple-leg shovel-nosed lobster) for T. unimaculatus. It is evident that there is some ecological separation of the different species, and we hope this increased knowledge can be used to help establish sustainable management of their exploitation in Thailand.

Key words: Cytochrome c oxidase subunit I, Molecular phylogenetics, Shovel-nosed lobster, Thailand, Thenus.

*Correspondence: Tel: 66-22185378. Fax: 66-2-2185386. E-mail:jessada.d@chula.ac.th