Notes on the genus Pterygosquilla Hilgendorf, 1890 (Stomatopoda: Squillidae) in Chile

Abstract

Pterygosquilla is a large-size genus of the stomatopod family Squillidae. It contains four species of which two, P. armata (Milne Edwards H, Histoire naturelle des crustaces, comprenant l'anatomie, la physiologie et la classification de ces animaux 2, 1837) and P. gracilipes Miers, 1881, have been recorded in the Americas. Three subspecies of P. armata (P. armata armata, P. armata gracilipes, and P. armata capensis Manning, 1969 were recognised by Manning (Stomatopod Crustacea of the western Atlantic, 1969) but Ahyong (The Marine Fauna of New Zealand: Mantis shrimps (Crustacea: Stomatopoda); 125: 1-111, 2012) showed they should be separate species. New material of Pterygosquilla armata was collected off the coast of Chile, in the eastern Pacific and was compared with previous descriptions available in the literature for P. armata, to the type material of Squilla gracilipes and to additional museum specimens of this species. Special attention was given to the lateral processes of the abdominal somites in both species. Four males and one female of P. armata collected off Quellon, Punta Lapa, Chile, were studied. They share several diagnostic characters with typical P. armata and also feature a previously unknown character: a remarkable, wing-like, thin lateral extension of abdominal pleura representing up to 50 % of the specimens total width. These extensions had been previously reported for the other American species, P. gracilipes, by Parisi (Elenco degli stomatopodi del Museo di Milano; 61:91-114, 1922). The type material of Squilla gracilipes, held at the Natural History Museum in London, however, lacks these lateral extentions, probably because it is a much smaller specimen. The material reported from off Chile represents a wing-like form of P. armata in which the lateral processes of the abdominal pleura are strongly expanded.