7006

• UCREFRP Catalog Number: 7006
• Author: Gustafson, E.
• Title: Early Development, Adult Sexual Dimorphism, and Fecundity of the Razorback Sucker,
• USFW Year: 1975
• Copyright Material: NO

'r

r ,

. . 1 '/". 'I
~roxlma~e yoa rlver ~1 os

north

of Da~is Da2; (2) in a small cove

LLl CottoJ:lJiood .i3asi'n approAimat..ely 20 river mlles north of Davis

Dam (1"1g. 1). A total of 101 Xyra.ucher. ';'jas netted; and, of these,

40 males and 29 females were traJ.lsported to a raceway at the Willow

Beach National Fish f...atchery for propagation. Tilirty-two addi tion-

al suckers' were returned to.the reservoir after local, antifungal

treatment of net marks and external parasites with a potassium per-

manga.l.late (KNJ..04) solutio{l.

Nost of the cap t; ured males Here still in 8.!1 ac. ti ve spawni,d.g

condi tiO.il. but the females had 8i ther spawned or tileir eggs had not

yet matured. Therefore,~suitable female suckers were injected with

human Chorio{liG Gonado :;ru ~in (rlCG) , a general hormo.na1 agent whic!l

induces oBcyte maturacion. ~ubsequent to interparitoneal injection

of HCG. roughly:5.00Geges \iere stripped from a single fertale and.

immediately fertilized wich the sperm of two, males, as observed in

nature (Douglas. 1952): Developing embryos obtained from this un~

ion were maintained ill an indoor raceway at the hatchery for 28

hours. 'l'empera-cures in t:1e race...ay ranged from 1J to 170C. During

t.he secoild da,j. three-quarters of the eggs were transferred to a-

quaria at. Ari ZO~la S ~.3.te UH1"lic.csi ty i'ihere Qevelopi:ient cOl1tinued at a

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