Reference: />'/,</. Hull., 150: 286-293. (April, 1976) EFFECTS OF SALINITY AND TEMPERATURE ON THE DEVELOP-MENT OF EGGS IN THE TUBE BUILDING AMPHIPOD COROPHIUM TR1AENONYX STEBBING K. SHYAMASUNDARI Department of Zoology, Andhra University, Waltair, South India The amphipod Corophium triaenonyx is a fouling organism living in parchment tubes on timber and concrete jetties. It is a hardy form, tolerating wide ranges of salinity and temperature under laboratory conditions ( Shyamasundari, 1973). It occurs abundantly throughout the year with peak numbers between November and March (Shyamasundari, 1972). It is generally agreed that salinity and temperature play a major role in the development of embryos. The rate of embryonic development has been reported in several cases to be affected by salinity and the variation in salinity may modify the time and length of breeding season. Temperature fluctuations may enlarge or narrow the salinity range of the species and the salinity in turn may influence the temperature tolerance (Kinne, 1952; 1953a; 1956a; 1957; 1958a; and 1959). There have been quite a number of studies on reproduction and development in amphipods but contributions towards the effects of salinity and temperature or the combined effects of these parameters on development have been documented by a few papers. Most of the literature is based on field observations. Clemens (1950) studied the effect of salinity and temperature on the incubation period (time between fertilization and hatching) in Gannnanis jasciatus. Bovie (1951) dealt with the pre-embryonic, post-embryonic and adult stages of Hyalclla aztcca. Kinne (1953a; 1959; I960; 1961; and 1964) furnished information on the effects of salinity and temperature and their combined effects on the development of embryos, number of eggs and upper limiting temperature for embryonic develop-ment in Gannnanis dncbcni. Hynes (1954) showed the differences in the capacity of egg laying between freshwater and brackish-water forms of Gcnnitants ducbcni. McLusky (1967; 1968) has given some details about the effects of salinity on survival, molting and growth activities of Corophium volutator. Vlasblom and Bolier (1971) studied the tolerance of embryos of Marino gammarus marinus and OrcJicstia gaiinnarclla to low salinities. The duration of embryonic development at various temperatures in Gaiinuants dncbcni. Gannnants lawrencianus, Gani-inanis obtnsatiis, Gannnants occanictts and Gannnants sctosits was studied by Steele and Steele (1973). Dorgelo (1974) discussed the effect of salinity and temperature combinations on Chactogainniants marinus, Gammarus ti grin us and Gaiinuants forsannn from marine, freshwater and brackish-water, respectively. Shyamasundari and Hanumantha Rao (1974) furnished some details about the effects of temperature on the embryonic and post-embryonic stages of Corophium triaenonyx. An experimental study has been undertaken in order to ascertain more pre-'ly the effects of salinity and the combined effects of salinity and temperature on the development of eggs in C. triaenonyx. 286
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