A study was conducted at Yaquina Bay, Oregon, to determine
the age-fecundity relationships in the striped seaperch Embiotoca
lateralis. A questionnaire was sent to California, Oregon, and
Washington to ascertain what regulations were in effect, and the value
of the family Embiotocidae with regard to the sport and commercial
harvest. The questionnaire revealed that no state maintained a
systematic account of each species landed, and further life history
data appeared desirable for sport and commercial species.
Fish were collected from March 20 to August 21, 1960, with
140 females and 26 males being collected for analysis by hook and
line or 125-foot experimental gill net. Scales were imprinted on cellulose
acetate cards or mounted between glass slides, The catch was
measured in centimeters of standard length and weighed in grams.
From 123 females, 2, 654 embryos were obtained, and a maximum of 22
embryos per female was measured in millimeters of standard length.
The estimated time of annulus formation in most scales was
from March 15 to June 12. Second and third annuli were primarily
laid down in March and April, with the probable peak of annulus formation
for females of ages IV, V and VI in May. Length-frequencies
were presented by age-class and sex. Eighty-one females of age-class
III dominated the sample. Females of age-classes II and III
attained greater average lengths than males. In age-class II, average
weights for females were slightly greater than those for males.
Both sexes generally mature for the first time in their third year of
life.
Length-weight, and length-number of embryos per female, for
females of age-classes III-IV, were expressed by the regression
equation Y[subscript c] = a+ b (X). High correlations for length-weight were ob-
tained. Additional females were needed to evaluate that age when
weights would digress. Females of age-class V produced the most
embryos per unit increase in length; this rate declined in age-class
VI. The largest number of embryos produced by an age class was
1, 431, in age-class III. The average number (in parentheses) of
embryos produced per female of each age class, was: II ( 17); III
(18); IV (21); V (30); VI (31) and VII (32). The most prolific female
was seven years old and contained 45 embryos.
Sixteen diminutive embryos were collected in 10 out of 128
mature females. Most older females were thought to have ovulated
earlier than younger females, for their embryos were generally
larger than embryos of younger females. However, embryos from
younger females could reach the approximate mean size of embryos
of older females, but at a later date. Birth of embryos began about
June 12 and ended in late July. Embryos averaged about 50 mm in
standard length at birth.
Suggestions are given for management of the striped seaperch. / Graduation date: 1966
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37274 |
| Date | 27 July 1965 |
| Creators | Swedberg, Stephen Ernferd |
| Contributors | Bond, Carl E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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