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Embryonic development of the platyfish (Platypoecilus), the swordtail (Xiphophorus), and their hybrids. Bulletin of the AMNH ; v. 94, article 4

Show simple item record Tavolga, William N., 1922- en_US 2005-10-06T14:44:36Z 2005-10-06T14:44:36Z 1949 en_US
dc.description p. 165-229 : ill. ; 27 cm. en_US
dc.description Thesis (Ph. D.)--New York University. en_US
dc.description Includes bibliographical references (p. 227-229). en_US
dc.description.abstract "One. Embryonic development of the viviparous poeciliid fish Platypoecilus maculatus may be conveniently divided into 26 stages for descriptive purposes. 2. The embryonic growth rate for P. maculatus is determined by comparison of morphological age (in terms of embryonic stage) with theoretical age (days after the birth of a previous brood). This comparison is based on a series of embryonic broods obtained by laparotomy at various times during the twenty-eight- to thirty-day reproductive cycle of this species. 3. A study of growth and organogenesis in P. maculatus reveals the following features: A. The concomitant regression of the extra-embryonic membranes and the yolk mass is accompanied by a drop in the slope of the growth curve. B. The initial formation of the extra-embryonic membranes takes place in a manner similar to that in the 'amniotes.' C. Cleavage, gastrulation, and neurulation follow a course basically similar to that of other teleosts. D. Blastopore closure occurs after tail bud formation. E. The notochord forms directly from endoderm by delamination. F. Pigment formation is evident first in the retina and subsequently in the choroid and meningeal coats. G. Kupffer's vesicle (post-anal gut) contributes to the development of the urinary bladder. H. The formation of the ventral aorta and aortic arches is described with regard to the reversal of blood flow in the ventral aorta and the change of position of the sinus venosus during yolk regression. 4. Comparisons with other species of Platypoecilus (P. variatus, couchianus, and xiphidium) reveal no significant differences in embryonic development. 5. Platypoecilus maculatus development, compared to that of Xiphophorus hellerii and Platypoecilus-Xiphophorus hybrids, shows the following differences: A. Initial pigment differentiation in Xiphophorus occurs one stage later than in Platypoecilus. The hybrids form pigment at the same stage as Platypoecilus or earlier. B. Over the same period of time, Xiphophorus embryos attain a larger size than Platypoecilus embryos. The growth rates of the hybrids all coincide with or exceed those of Xiphophorus. C. Caudal fin differentiation is one stage later in Xiphophorus than in Platypoecilus. However, all the hybrids form a caudal fin at the same rate as P. maculatus, and the F[subscript 1] X Platypoecilus backcross hybrid embryos exceed both parental species in this respect. 6. Sterility and embryonic anomalies are frequent among hybrid females. This is particularly true of F[subscript 1] females possessing the Sd (spotted dorsal fin) character, indicating a linkage of lethal factors with this pattern gene"--P. 226. en_US
dc.format.extent 15609314 bytes
dc.format.mimetype application/pdf
dc.language eng en_US
dc.language.iso en_US
dc.publisher New York : [American Museum of Natural History] en_US
dc.relation.ispartofseries Bulletin of the American Museum of Natural History ; v. 94, article 4 en_US
dc.subject.lcc QH1 .A4 vol.94, art.4, 1949 en_US
dc.subject.lcsh Platies -- Development. en_US
dc.subject.lcsh Xiphophorus -- Development. en_US
dc.subject.lcsh Swordtails (Fish) -- Development. en_US
dc.subject.lcsh Fishes -- Embryology. en_US
dc.subject.lcsh Hybridization. en_US
dc.title Embryonic development of the platyfish (Platypoecilus), the swordtail (Xiphophorus), and their hybrids. Bulletin of the AMNH ; v. 94, article 4 en_US
dc.title.alternative Embryonic development in fish en_US
dc.type text en_US

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  • Bulletin of the American Museum of Natural History
    The Bulletin, published continuously since 1881, consists of longer monographic volumes in the field of natural sciences relating to zoology, paleontology, and geology. Current numbers are published at irregular intervals. The Bulletin was originally a place to publish short papers, while longer works appeared in the Memoirs. However, in the 1920s, the Memoirs ceased and the Bulletin series began publishing longer papers. A new series, the Novitates , published short papers describing new forms.

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