Sorry I missed this earlier Bill. More long-haired stuff - there is a bunch.

Note - The scientific name of Warmouth has been changed thus Lepomios gulosus = Chaenobryttus gulosus



Phylogenetic Relationships of Sunfishes as

Demonstrated by Hybridization *

F. EUGENE HESTER

Via AFS

MATERIALS AND METHODS

These experiments were conducted by using

artificial stripping and fertilization techniques.

Male fish of each species were held in aquaria

in the laboratory where photoperiod and water

temperature were maintained at approximately

that existing at the time of natural spawning.

Ripe females were seined or trapped from

spawning areas and broughto the laboratory.

If necessary, they were given hormone. in-

jections of chorionic gonadotropin as. recom-

mended by Stevens (1966) to induce ovula-

tion. Eggs were stripped from a female into

several Syracuse watch glasses. Milt was

extruded by manual pressure and was col-

lected in medicine droppers. Eggs were fer-

tilized in watch glasses. Conspecific, inter-

specific and intergeneric crosses were made.

After the gameres were mixed, a small

amount of water was added. About ten

water and the watch glasses were filled with

water. Fresh water was added about three

times each day. The eggs were incubated in a

room maintained at approximately the normal

spawning temperature for the maternal parent.

Fertilization success was measured after

cleavage was obtained and hatching success

was measured after hatching was complete.

Hatching success was evaluated in relation to

hatching of the control cross by considering

the control cross success to be equal to 100%

and expressing the hybrid cross success as a

percentage of the control cross success.

Experiments were also conducted to mea-

sure the frequency and duration of partheno-

genetic development of sunfish eggs.

Twenty-three hybrid crosses (5 interspecific

and 18 intergeneric, including some recipro-

cals) were attempted, using 11 species of

fishes representing 7 genera.



West (]968) showed

that while Micropte'rus salrnoides X Chaeno-

bryttus gulosus hybrids could easily be pro-

duced and reared, they were sterile. The cross

of Chaenobryttus gulosus female X Lepornis

rnacrochirus male was more difficult to pro-

duce and rear (there were no survivors to

fingerllng size in the reciprocal cross), but

they wcrc fertile. This indicates a closer

phylogenetic relationship between Chaenobryt-

tus and Lepomis than is indicated by hatching

success (Figure 3). Chaenobryttus gulosus X

Lepornis rnacrochirus hybrids have also been

reported as naturally occurring populations

(Hubbs, 1955; Birdsong and Ycrger, 1967)

and have been artificially produced (West

and Hcster, 1966; Childers, 1967).



Another source

TEMPO OF HYBRID INVIABILITY IN CENTRARCHID FISHES

(TELEOSTEI: CENTRARCHIDAE)

DANIEL I. BOLNICK AND THOMAS J. NEAR











The only crosses with total inviability in

both directions are M. salmoides X (Ambloplites rupestrus,

Pomoxis annularis, or Pomoxis nigromaculatus) at 28.94 million

years, while 10 other crosses of that age have some

viability in one or both reciprocal directions (see online Appendix).

Centrarchids also retain nonzero viability and heterosis

for much longer than most other taxa.



Last edited by ewest; 03/25/08 12:55 PM.