Aspects of the biology of Platorchestia fayetta sp. nov. (Crustacea, Amphipoda) at Poste La Fayette, Mauritius

Abstract

Amphipods form an important component of coastal fauna and this study is focused on the biology of semi-terres- trial Platorchestia fayetta sp. nov. inhabiting sand and wave-cast algae on the north-eastern coast at Poste La Fayette, Mauritius. The population structure, size class variation, sex ratio and female reproductive status of the species were studied during the summer months (October 2015 - February 2016). The number of Platorchestia fayetta sp. nov. decreased considerably throughout the study period. Incubating females were present in all samples collected and ranged between 2.1 to 5.1 mm in size, with the larger ones brooding more embryos. The species can be described as multivoltine having a life history strategy of type I, whereby production of o spring occurred continuously. The average male body size ranged between 4 - 5 mm and was signi cantly larger than females in most months. Sex ratio was always female biased. This study adds to the knowledge on the biology of the species. Such informa- tion is important to understand the population structure of Platorchestia fayetta sp. nov. and their interaction with the changing environment.