Survey of large branchiopods on Aruba and observations on taxonomic characters in Leptestheria (Spinicaudata)

A survey of more than 60 ephemeral pools during March 1989 resulted in finding three large branchiopods not previously known to occur on the Caribbean Island of Aruba. These were two Anostraca, Dendrocephalus spartaenovae Margalef, 1967 and Thamnocephalus venezuelensis Belk & Pereira, 1982, and one Spinicaudata, Leptestheria venezuelica Daday, 1923. The notostracan previously reported from Aruba, Triops longicaudatus (LeConte, 1846), was also collected from several pools. All of these species occur also in Venezuela, which is separated from Aruba by an ocean gap of about 25 km. Comparison of Leptestheria venezuelica with Leptestheria compleximanus (Packard, 1877) demonstrated that cephalic morphology provides useful taxonomic features including length of rostrum, depth of occipital notch, shape of the occipital region, and protrusion of the eye capsule. These features may prove useful in studying other species of Leptestheria.