New Branchinella (Anostraca) From Texas, U.s.a., and the Problem of Antennalike Processes

Abstract

With this report, four species of the anostracan genus Branchinella are known from North America. Two occur in the state of Texas and one each in the states of Georgia and Florida. The two east coast species probably need to be brought under protection of endangered species laws, since they have been reported only from their type localities. For the first time outside the genus Dendrocephalus, we found antennalike processes between the first and second antennae on the heads of males in a new Branchinella from Texas and the two east coast species with which it seems closely related. Linder (1941) reported what he called fingerlike processes proceeding frontally from the bases of the eyes of males of an Australian species of Branchinella and wondered if they were comparable with the antennalike processes found in species of the New World genus Dendrocephalus. Our finding of antennalike processes in three New World species of Branchinella suggests that homology is a strong possibility. While species of Branchinella are the numerically dominant anostracans in Australia (Geddes, 1983), they are among the least common fairy shrimps in North America. Including a new species described herein, all four North American Branchinella have distributions confined to the United States. Of these, B. lithaca (Creaser, 1940) and B. alachua Dexter, 1953, have been reported only from their type localities in Georgia and Florida, respectively. The status of these merits investigation, since they are very likely in need of protection under threatened and endangered species legislation. A third previously described species, B. sublettei Sissom, 1976, has an apparently safe distribution in western Texas. Home (1974) found it in six saline playas in three counties on the Llano Estracado south of Lubbock.