A new polymorphic species of Leptochelia (Crustacea: Tanaidacea) from Guinea Bissau, West Africa, with comments on genetic variation within Leptochelia

Abstract

A new species of Leptochelia, namely L. africana, is described from Guinea Bissau, West Africa, following the collection of specimens during the Laboratory of Marine Community Ecology and Evolution's sampling expedition to Macaronesia and Portugal's former colonies. Genetic and morphological analysis separates this species from the other east-Atlantic species of Leptochelia, a genus known for its combination of many cryptic species, considerable intra-specific variation, and multiple morphological forms. The diagnostic characters of the female are: antennule proximal article more than 3 times as long as wide, article 2 not longer than article 3; dorsodistal spiniform seta on antennal article 2 weaker than ventrodistal; setae not arising from a process; maxilliped basis with three distal setae longer than endites, palp article 2 with outer spiniform seta arising from a process; uropod exopod biarticulated, longer than proximal endopod article; and endopod terminal article longer than other articles. The males are structurally more complicated and cannot be assigned diagnostic characters based on morphology alone. The primary males have an uniarticulated uropod exopod, whereas that of the secondary males is biarticulated.