98 



JAMES W. ATZ 



Family Tetraodontidae : 



Puffer, Fugu pardalis (Timminck and 

 Schlegel). [Shojima, 1957.] 

 Family Batrachoididae : 



Oyster toadfish, Opsanus tau (Linnaeus). 

 [Straughan, 1957; Tracy, 1959; Dovel, 

 I960.] 



From this list it can be seen that less 

 than 30 species of marine teleosts have 

 ever been reared in captivity from the egg. 

 The few successes achieved can be attrib- 

 uted, in general, to two causes. The first 

 concerns those economically important 

 species on which it has been worthwhile to 

 spend a good deal of time and effort (At- 

 lantic herring, Atlantic cod, and the flat- 

 fishes), and the second those species with 

 well-developed hatchlings or with special 

 means of parental care, either of which 

 might be considered to preadapt them to 

 successful reproduction in the laboratory 

 (sticklebacks, tube-snouts, seahorses, ath- 

 erinids, surf perches, and toadfishes). We 

 were surprised not to find any papers 

 that describe the raising of Fundulus het- 

 eroclitus or some other marine cyprino- 

 dont in captivity, because members of the 

 family Cyprinodontidae would seem to be 

 eminently suitable for this kind of labora- 

 tory life. The eggs of the mummichog are 

 easy to obtain and hatch (Gabriel, 1944; 

 Costello et al., 1957), and the young have 

 been raised to adulthood with simple 

 equipment and relatively little effort (Al- 

 fred Perlmutter, New York University, 

 personal communication). We have also 

 seen sheepshead minnows {Cyprinodon 

 variegatus) hatch from eggs laid in one 

 of our exhibition aquariums and grow to 

 near maturity with no special care what- 

 soever. 



The work of Triplett (1960) indicates 

 the possibility of culturing the young of 

 the viviparous surfperches throughout the 

 period of embryonic development, which 

 would normally be spent within the 

 ovary— just as that of Trinkaus and Drake 

 (1952) had previously shown for the well- 



known poeciliid, the guppy. Perhaps sim- 

 ilar techniques could be applied to the 

 other types of livebearing marine fishes, 

 i.e., the Clinidae (kelpfishes), Zoarcidae 

 (eelpouts), and Brotulidae (brotulas). 

 Those scorpionfislies and rockfishes of the 

 family Scorpaenidae that bring forth liv- 

 ing young are truly ovoviviparous, how- 

 ever, and their newborn young are no fur- 

 ther developed than those of the scorpae- 

 nids that lay eggs; indeed, Morris (1956) 

 was unable to carry newly born Seha-stodes 

 goodei to metamorphosis. A priori, it 

 would seem that the best chance for suc- 

 cess would be with a form lying some- 

 where between the extremes of true ovo- 

 viviparity and viviparity, since the latter 

 would involve placentalike structures and 

 almost complete dependence of offspring 

 on mother for nutrition, for which it 

 might be as difficult to find an adequate 

 substitute as it has been in the mammals. 

 The elasmobranchs run a similar gamut 

 from ovoviviparity to viviparity, but no 

 attempts to grow in vitro the embryos of 

 sharks, dogfishes, rays, sawfishes, or gui- 

 tarfishes seem to have been recorded. On 

 the other hand, the large eggs of the ovip- 

 arous sharks and skates have proved ex- 

 cellent experimental subjects (Vivien, 

 1941, 1954). 



Whether the eggs and young of the ma- 

 rine fishes that practice oral incubation 

 would be especially suited for laboratory 

 culture is a pertinent question. Shaw and 

 Aronson (1954) and Shaw (1957) have 

 shown that the eggs and young of one of 

 the fresh-water, mouth-breeding cichlids 

 can be cultured outside the parent's mouth. 

 There appears to be no reason why similar 

 techniques would not work with the sea 

 catfishes (family Ariidae), altliough there 

 miglit be a problem in feeding the young 

 fish, which are known to ingest food dur- 

 ing the latter part of the 2-month period 

 spent in the father's mouth. In the cardi- 

 nalfishes (family Apogonidae) and jaw- 



