. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SHRIMP ABUNDANCE AND DISTRIBUTION 1S1 Sexual dimorphism is also apparent in P. macrodactylus. Almost all indi- viduals longer than 40 mm were female. Females reached ca. 55 mm maximum length and males ca. 44 mm. This is near previously reported sixes (Newman, 1963). Size at sexual maturity was not determined but secondary sexual char- acteristics are apparent when shrimp attain about 20 mm in length. Ovigerous females as small as 23 mm long were collected, so males would presumably mature at this or smaller sizes. Length-wei
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SHRIMP ABUNDANCE AND DISTRIBUTION 1S1 Sexual dimorphism is also apparent in P. macrodactylus. Almost all indi- viduals longer than 40 mm were female. Females reached ca. 55 mm maximum length and males ca. 44 mm. This is near previously reported sixes (Newman, 1963). Size at sexual maturity was not determined but secondary sexual char- acteristics are apparent when shrimp attain about 20 mm in length. Ovigerous females as small as 23 mm long were collected, so males would presumably mature at this or smaller sizes. Length-weight relationships for juvenile, male and female specimens of C. jranciscorum are presented in Figure 5. The regression equations describing these relationships are given below : Juveniles (n " 100) : log W = + log L, r ^ Males (n == 74) : log W + log L, r == Non-ovigerous females (n = 57) : log W : — + log L, r = (W = dry weight in grams and L = total length in mm). Analysis of covariance (Steel and Torrie, 1960) revealed significant differences in slopes between the length-weight regression of juveniles and mature shrimp. The difference is attributable, at least in part, to gonadal development. Length—weight relationships for P. macrodactylus are presented in Figure 6. Regression equations describing these relationships are given below: juveniles (n = 118) : log W = + log L, r == Males (n == 45 ) : log W + log L, r = Non-ovigerous females (n = 19) : log W = + log L, r == The slopes of the above regressions are all significantly different from one another (« = ). P. macrodactylus is more robust than C. jranciscorum, in many cases weighing 50*/£ more than a C. jranciscorum of similar length. Ovigerous specimens of C. jranciscorum were collected in San Pablo and San Francisco Bays in the spring and fall of 1977. Most female specimens of C. jranciscorum collected in San Fra
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
