Spatial and temporal variation in superfoetation and related life history traits of two viviparous fishes: Poeciliopsis gracilis and P. infans

Abstract

Superfoetation is the ability of females to simultaneously bear multiple broods of embryos at different developmental stages. Most studies on the phylogenetic distribution of superfoetation and on the factors that potentially promote superfoetation ignore variation within species. Here, we studied 11 populations of two species of viviparous fishes of the family Poeciliidae (Poeciliopsis gracilis and Poeciliopsis infans) and document wide variation in superfoetation and in three related life history traits: brood size, individual embryo mass and total reproductive allotment. We found significant differences in the average number of simultaneous broods among populations of P. gracilis but not among populations of P. infans. In addition, we found even greater variation between months within populations for both species, although no specific pattern of temporal variation was evident. Instead of the expected consistency of seasonal differences in superfoetation across populations, we found that large variation among months within seasons and the amount and direction of this monthly variation differed widely between populations. Our results emphasize the importance of including intraspecific variation in superfoetation and other life history traits in studies that aimed at finding general explanations of life history trait evolution.

Morphological structures for potential sperm storage in poeciliid fishes. Does superfetation matter?

“…In general, spermathecae are considered a morphological mechanism that allows a continuous supply of spermatozoa, facilitating reproduction when there is a low abundance of males or when reproductive cycles are asynchronous (Birkhead & Møller, 1993;Gist & Congdon, 1998). However, in populations of poeciliid fishes, males are abundant and females are receptive year-round (Frías-Alvarez, Garcia, V azquez- Vega, & Z uñiga-Vega, 2014;Houde, 1997). Therefore, it is unlikely that in poeciliids these are the main functions of sperm storage within spermathecae.…”

Superfetation in the viviparous fish Heterandria formosa (Poeciliidae)

“…The degree of superfetation can be expressed as the average number of broods of embryos that a female carries with morphological differences in well‐separated stages of development (Pires & Reznick, ; Turner, ). The degree of superfetation is not a static parameter for each species but presents plasticity and varies between members of the same species (Frías‐Alvarez et al, ; Leips & Travis, ; Pires et al, ), as was observed in H. formosa .…”

“…In teleost fishes, the degree of superfetation (the number of broods in simultaneous development), varies according to the species and environmental and ecological factors, for example, lotic and lentic water systems, velocity of water, food availability, population density, and temporality according to the season. The factors that promote and maintain the superfetation are uncertain (Frías‐Alvarez, Macías‐Garcia, Vázquez‐Vega, & Zúñiga‐Vega, ; Frías‐Alvarez & Zúñiga‐Vega, ; Leips & Travis, ; Turner, ; Zúñiga‐Vega et al, ; Zúñiga‐Vega, Reznick, & Johnson, ).…”

Predation effects on matrotrophy, superfetation and other life history traits in Phalloceros harpagos

“…Most attempts to understand the evolution of superfetation have focused on differences among species (Meisner & Burns, ; Reznick & Miles, ; Thibault & Schultz, ). However, some studies have shown that intraspecific comparisons may be more promising, as comparison among populations of the same species exposed to different selective forces may reveal causes responsible for phenotypic divergence (Frías‐Alvarez, Garcia, Vázquez‐Vega, & Zúñiga‐Vega, ; Frías‐Alvarez & Zúñiga‐Vega, ; Travis, Farr, Henrich, & Cheong, ; Zúñiga‐Vega et al., ). Indeed, environmental heterogeneity (e.g., differential predation pressure) can also drive variations in matrotrophy and superfetation, as observed in our study.…”