Medlen, 1951


Medlen, A.B. (1951) Preliminary observations on the effects of temperature and light upon reproduction in Gambusia affinis. Copeia, pp. 148-152

Associated characteristics

Species Development state Trait Primary Data Secondary Data
Gambusia affinis Female Length at sexual maturity Nine females comprised three large individuals (4.5-5 cm) in length born the predecing year, three middle-sized individuals (2.5-3 in length) born early in the year 4.75 cm
Gambusia affinis Female Female sexual dimorphism A small pigmented spot dorsal to the anus occurs in female poecilliid fishes before they are matured. As they become mature and gravid, the spot becomes larger reaching its maximum size shortly before the birth of the brrod. This prigmented spot is referred to as the "gravid spot". After the brrod is born, the gravid spot recedes, but there is never a complete loss of the pigmented mass. Absent
Gambusia affinis Male Male sexual dimorphism Nine females and two mature males, as determined by the number of segments in the third ray of the gonopodium Absent
Gambusia affinis Spawning conditions Spawning temperature Critical temperature sould be near 15.56°C 15.56 °C