Systematic Relationships amongst Lobsters that with Claws (Crustacea: Decapoda: Polychelida, Homarida)

• Main Authors: Chang, Su-Ching, 張素菁
• Other Authors: Chan, Tin-Yam
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/52873741881907299450

博士 === 國立臺灣海洋大學 === 海洋生物研究所 === 104 === “Lobster with claw” refers to the members within Polychelida and Homarida. They also belong to the controversial taxon Macrura Reptantia, which contains four infraorders, namely Achelata, Glypheidea, Polychelida, and Astacidea (including Astacida and Homarida). There are extensive molecular phylogenetic analyses on Achelata, Glypheidea, as well as freshwater crayfishes (i.e. Astacida). However, limited molecular phylogenetic works have been focused on Polychelida and Homarida. The present work constructs molecular phylogenetic trees on Polychelida and Homarida on a broad taxonomic coverage. During specimen sourcing and molecular analyses, two new Thaumastocheles species from the Indo-West Pacific and five Taiwanese new records (four in Polychelidae and one in Nephropidae) have been reported. The present molecular topologies supported the current genera in Homarida but suggested at least one new genus should be erected for Polychelidae. 44 and 37 synapomorphies are identified in Polychelidae and Homarida, respectively. Extant polychelids are likely originated from either eastern Atlantic or the Mediterranean Sea in the Late Cretaceous. The more derived genus Willemoesia with shorter eye stalks and deepest bathymetrical distribution supports the onshore-offshore shift in polychelidan lobsters. The homaridan lobsters, on the other hand, divided into two main clades, corroborating the two families presently recognized in this group (i.e. Enoplometopidae, Nephropidae). The two genera scheme in Enoplometopidae is well supported and can be separated by the number of spines on lateral margin of telson. Enoplometopid lobsters likely originated from northwestern Pacific in the Early Jurassic and then dispersed into the Atlantic through the Mediterranea. Two of the three subfamilies in Nephropidae are shown to be invalid. Several characters believed to be synapomorphies in Homarida from previous morphological analyses are revealed to be convergent characters. Acanthacaris occupied the earlier branch in Nephropidae, however, the origin of nephropid lobsters is unclear though most genera in this family have their origin and dispersal pathway identified. The three thaumastocheliform genera (i.e. Dinochelus, Thaumastocheles, Thaumastochelopsis) could originate from Europe in the Late Cretaceous. Metanephrops may evolve from southern high latitude. Those monophyletic nephropid genera mainly restricted in the southern hemisphere may disperse via West Wind Drift (WWD). A phylogenetic molecular analysis with broader taxonomic coverage on Reptantia still cannot fully resolve if Macrura Reptantia is a valid taxon.