Reference: Biol. Bull., 136: 114-129. (February, 1969) OSMOREGULATORY CAPACITIES OF CALLIANASSA AND UPOGEBIA (CRUSTACEA: THALASSINIDEA) 1 LAWRENCE C. THOMPSON AND AUSTIN W. PRITCHARD Department of Zoology, University of California, Berkeley, California, and Department of Zoology, Oregon State University, Corvallis, Oregon The thalassinid burrowing mudshrimps are an example of a group of decapod Crustacea about which relatively little is known with respect to osmoregulatory capacities. A few pertinent physiological studies have yet to become common coin of the scientific literature. Thus, like several invertebrates of rhe Black Sea, Upogebia ( = Gebia) littoralis was shown to regulate its osmotic concentration in brackish waters (Zenkewitch, 1938). Recent unpublished research demonstrated the strong osmoregulatory capacities of the African mudshrimps Upogebia africana and U. capensis (Hill, 1967). On the other hand, it has been reported that U. affinis of eastern North America survived dilutions of sea water (SW) only to a very limited extent (Pearse 1945). Limited tolerance to diluted SW was also indicated for Upogebia sp. and Callianassa affinis of western North America (Gross, 1957). Although no data were given for thalassinids in his study, Gross concluded that both species are osmo-conformers. Subsequently the genera Callianassa and Upogebia have been characterized as "polystenohaline" Crustacea with ionic and volume regulation but with little or no osmoregulation (Brown and Stein, 1960; Lockwood, 1962; Kinne, 1963). As burrowers in marine sediments since at least the Cretaceous Period (Milne Edwards, 1861; Borradaile, 1903), callianassid and upogebiid crustaceans are widely distributed and such distributions include estuarine or other brackish situations (Schmidt, 1921; de Man, 1927, 1928; Pohl, 1946; Day, 1967). The distribution of Callianassa filholi of Australia and New Zealand suggests that this species may well experience brackish conditions (Devine, 1966). C. turnerana of Africa migrates annually or semi-annually from brackish water bays up fresh-water (FW) rivers and streams, a phenomenon so marked that the Cameroons derives its name from it (Monod, 1927). C. kraussi of Africa has a known salinity range of 1.25 59.5%e (Day, 1951). Both C. californiensis and U. pugettensis survived the storm inundation of Newport Bay, California (MacGinitie, 1939). Such accounts suggest the euryhalinity of those thalassinids concerned but published physiological evidence for the osmotic capacities of thalassinid Crustacea is generally lacking. This study compares osmoregulatory capacities in Callianassa californiensis, Upogebia pugettensis and U. affinis. Preliminary results for C. filholi of New 1 Part of this paper is based on a thesis submitted by L. C. Thompson in partial fulfillment of the requirements for the M. A. at the University of California, Berkeley. Research supported by NSF Grant GB 4792 and NIH Grant GM 13241-01 at the Marine Science Center, Newport, Oregon, and by NIH Fellowship 1-F1-GM-34, 529-01 at the Bodega Marine Laboratory, Bodega Bay, California. 114
BioStor
