Life Histories and Distributions of Copper River Fishes (.pdf)

with several bony plates, giving them a more ancient appearance (Fig. 17). Coloration variesgreatly between populations, as do life histories. Marine, freshwater and anadromous forms areall in existence. Their varied life history strategies may contribute to their enormous success incolonizing many habitats.Figure 17. A typical threespine stickleback (Morrow, 1980).The marine forms move into shallow coastal waters to spawn in early spring, withspawning occurring in June and July. Male mating behavior is complex, and is a favorite subjectof animal behaviorists. Males build a barrel shaped nest of various materials found in theenvironment glued together by a specialized kidney secretion (Morrow, 1980). After an elaboratecourtship dance to draw a female’s attention, the receptive female may enter the nest to copulate.Males then tend the nest, and exhibit a remarkable degree of parental care. The male closelyherds newly hatched stickleback until they are large enough to swim off on their own.Stickleback may spawn several times in one season.Freshwater stickleback spawn in much the same way as marine forms, but inhabitshallow, well-oxygenated waters. Aquatic vegetation is often an important part of suitable habitatfor stickleback (Morrow, 1980). Anadromous forms spawn in similar fashion to marinestickleback, and can do so in either fresh or saltwater. Young anadromous stickleback then moveout of estuaries into the ocean. Stickleback feed on a variety of insects and zooplankton.There is little information in the literature to confirm that threespine stickleback inhabitthe Copper River. However, judging by their range and habitat preferences, it is likely that theymay be found in the system, especially in the lower stream reaches and in the Delta.Page 22 of 27