Burukovsky R.N.1, Romanov E.V.2 2020. Records of crustacean decapodid stages from the family Enoplometopidae (Crustacea: Decapoda) in the pelagic environment of the western Indian Ocean // Arthropoda Selecta. Vol.29. No.4: 443–451 [in English].
1 Kaliningrad State Technical University, 1, Sovetsky Prospect, Kaliningrad, 236022 Russia. E-mail: burukovsky@klgtu.ru
2 Centre technique de recherche et de valorisation des milieux aquatiques (CAP RUN – CITEB) 97420 Le Port, île de la Réunion E-mail: abyss.explorer.io@gmail.com
doi: 10.15298/arthsel.29.4.06
ABSTRACT. Juveniles of decapod crustaceans at the decapodid stage were recorded in the stomachs of top pelagic predators (Alepisaurus ferox, Thunnus alalunga, and T. albacares) caught in the oligotrophic gyre of the south-west Indian Ocean. Decapodods were found partially digested in stomachs. We were able to identify them and describe their morphological characters for the first time. These juveniles belong to the genus Enoplometopus (family Enoplometopidae de Saint Laurent, 1988, superfamily Enoplometopoidea de Saint Laurent, 1988, and infraorder Astacidea Latreille, 1802). 1. Enoplometopus pictus A. Milne-Edwards, 1862. Adults are only known from the holotype of species collected in Reunion Island.Our decapodids differs by their absence of armament on the outer margin of palms and fingers of chelae, as well as an absence of tubercles on the lateral surfaces of palms of the first pereiopods chelae. 2. E. holthuisi Gordon, 1968. It differs from other Enoplometopus species which possess two post-cervical spines with very thin cheliped. The length of the chela exceeds 50% of that of pereiopods; fingers length is slightly less than chela length. The chela width is 7.5 times its length. This species differs from E. gracilipes and E. voigtmanni that have a similar chela shape: the absence of two spines at the dorsal rear edge of the 6th abdominal somite (present in E. gracilipes), and by distribution range (E. voigtmanni). E. holthuisi records are known in Reunion Island while no occurrences of E. voigtmanni were recorded in the study area. Presence of E. holthuisi in the waters of Mauritius Island is reported for the first time extending documented distribution of this species in the Indian Ocean.
KEY WORDS: Crustacea, Decapoda, Enoplometopus pictus, E. holthuisi, Alepisaurus ferox, Thunnus alalunga, Thunnus albacares, decapodid, morphology description, Reunion Island.