Life history of the snake prickleback Lumpenus sagitta Wilimovsky, 1956

Graduation date: 1980Data are presented on the life history of snake\ud pricklebacks, Lumpenus sagitta, collected in Yaquina Bay,\ud Oregon, from June 1977 to October 1978. Specimens were\ud collected primarily by beach seine from four sampling sites\ud in the bay. Snake pricklebacks feed on algae (mainly genus\ud Enteromorpha), on polychaeta (mainly genus Neoamphitrite),\ud on crustacea (mainly harpacticoida), and other bottomdwelling\ud organisms. They were non-selective in feeding.\ud Based on gonado-somatic indices and egg diameter, I found\ud that snake pricklebacks probably spawn near the end of fall\ud and during winter. Fecundity was positively correlated\ud with standard length of the fish and had a correlation\ud coefficient of 0.85. The number of eggs per fish varied\ud from 2,277 to 6,100 with a mean fecundity of 4,089 eggs.\ud Otoliths are more useful than scales for determining the age\ud of the snake pricklebacks. There is agreement between ages\ud as established by the length-frequency method and those \ud established by the otolith method only until age two. The\ud length-weight relationship was described by the model\ud Ln W = Ln a + b Ln L. The value of the constant "b" was\ud lower than 3.0 for both males and females and varied from\ud 2.33 to 2.78. Females showed a larger constant "b" than\ud males during both years of sampling. Length and weight was\ud correlated for males and females and for sexes combined with\ud "r" values ranging from 0.94 to 0.98. In static bioassays,\ud low salinities (<1.0 ppt) and high temperatures (>20.0 C)\ud deleteriously affected the survival of snake pricklebacks