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

1~7j lliG~3Ured only

,. - . T
1. 0 alln.....la.iil~ ~t;;-". .

t1c.vlcver,

b.1' tiI:iJ.e of hat(;hi.L~g

but!. se;";:; or em'..:iryos haJ a~:'aL!ed equiv,-,ie.!lt le.ngtL.

~m';)r'yolog i cal DeveloT-iLlen:::

Stage 1: Unfertilized. Egg: Udj O. 0 hr;

1. 5 mm dia.

o irCl ar'e miL.;:.>' - ~'VLi te a.!lQ l.r'aHslucen".

Stage 2: ft'ertili zed .663: d.ay 1; 1 hI'; 1. 3 mm dia.
'.fhe ohor-iO.Ll i s ~"r&llS.i,.)d.re.ni:; ailQ the yolk is milky-v..hi te and
'i:.:caLls1u.ce,Ut. .An ani:;i-,,-l c...:.il is .Llot ,yet visible ~o the naked.. 8ye.

:Co8S are .'iat;er-hd..l'G..cl:..ed'al!J. have a gr'cacer specific gravit.y
trJan ,,'iate:c. 'Ihe CIlO:ciu.a is .:.d.hesi ve. uva are demersal and adhere
t.o substrate and to e&Ci1 oi:.her.

Si..age J:

"
.) nl'.
oegir.i..fli'..16 01 Cleavagt::. rllasL;or.J.eres are t.raJ...sparent: app.I'Ox.
0.5 mill total dia. Aaillicll and vegetal poles can liowbe distinguished
~y ~~e unaided eye.

2 rila3tu,,1e:cc::.s:

(Fig. Zed.

'l'~le O,ia are teloleci t;-,al d...:id cleaVage is Iilsroblast;ic.
t-l'esel.'vatio.Ll wi tl1 Al<'A cau;:;es causes d.nLllal cells to turn v;hi te
a.Lld becoH,e sOJlciNhaL opaque, 8.1h1. causes cila yolk to become yello\~-
~;i1i Le. the cho!'io~l rei:lctiliS t;l'8-..LlSpare.L.t af tel' preservation.
~tbge 4: 4 dlastomares: 5 hr.
-- '

2'lld. <;leavage. rllaSc.oiD.el'~s are approx. 1.0 m.m total d.ia.
~tdge 5: J Blastome:ces: 6 h,c.
J' ril (;leavGl.g~'. BL.l.s~oiJel'es HOW OCC;Upj' a 1. 2 by 0.8 mm rectau-
g:i.r' 011 tile anioal !iole.

. , ".J-
t>-cage v: 10 D.LastOJllE::res:

7 hr.

4' th Cleavag(:;.
S i-...l.ge 7: J2 Blastomeres: 9 hr.
5't,h Gleav8.g(,;.

( 1" ig . 20).

~~age J: 6~ rllbstumeres:
l:' l.li Gleav;...1.ge.

1 () nr.

~"~'-"Y_'~

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