ISSN:
1095-8649
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
In bitterling Acheilognathus rhombeus, developmental arrest always occurred at stage D of the free-embryonic phase, regardless of incubation temperature. Developmental arrest was terminated only by a cold treatment at 4° C for 60–90 days, initiated 10 days post-hatching. After the termination of developmental arrest, free-embryos became larvae c. 6 months after hatching, regardless of the time of initiation and duration of the cold treatment. In hybridization experiments between A. rhombeus and several species of spring-spawning bitterlings, free-embryos became free-swimming larvae within 60 days after hatching in all experiments. Developmental arrest was not observed in any of the hybrids, regardless of parental sex. These results suggest that free-embryonic diapause in A. rhombeus is not induced by environmental factors, such as cold, but by genetic factors, which are recessive to those in spring-spawning bitterlings. Free-embryonic diapause in A. rhombeus appears to be an adaptation to winter, which might have evolved with reproduction in autumn among autumn-spawning bitterling species. This is the only report of free-embryonic diapause after hatching in fishes, and only the second example of diapause in fishes, along with annual killifishes (Rivulidae).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.0022-1112.2005.00769.x
