The interrelation of the size of fish eggs, the date of spawning and the production cycle

Abstract

The variability in size of pelagic and demersal marine and freshwater fish eggs is examined.The difference between the smallest and largest volumes, based on published figures for the diameters, is large in many species. In marine species with planktonic eggs, the median percentage difference is just over loo%, and this is similar in species with demersal eggs and in freshwater fish.The available evidence suggests that geographical differences in egg size are small, hut in marine fish there is a well-known seasonal decline in egg size. In herring it has previously been shown that egg size in different spawning groups can be correlated with the timing of the production cycle. A similar correlation can be seen in the seasonal shift in time and locality of spawning, and egg size, of the plaice. Sufficient data on seasonal freshwater fish egg variations are not available, but the time of spawning does appear to be linked with the availability of food for the larvae in both lake and stream species.

Maternal effects and larval survival of marbled sole Pseudopleuronectes yokohamae

“…Egg sizes of multi-batch spawners have a tendency to decrease in the course of spawning (Bagenal, 1971;Chambers and Leggett, 1996;Chambers, 1997;Rideout et al, 2005). Large and old females of marbled sole are expected to spawn greater numbers of eggs and potentially surviving offspring, and they shoal in the early spawning period (mainly March).…”

Reproduction of Oligosarcus hepsetus (Cuvier, 1829) (Characiforms) in the Serra do Mar State Park, São Paulo, Brazil

“…Oligosarcus hepsetus showed fractional spawning, as did the same species in the Lajes reservoir , as well as Oligosarcus jenynsii (Hartz et al, 1997;HermesSilva et al, 2004) and Oligosarcus robustus (Nunes et al, 2004). This type of spawning is characterized by the synchronic development of oocyte lots in progressive stages of maturation, which will be eliminated along the reproductive period (Vazzoler, 1996), and is a frequent strategy of species living in stable (Mazzoni and Iglesias-Rios, 2002) and restricted conditions for the survival of eggs and larvae (Nikolskii, 1969;Bagenal, 1971;Jepsen et al, 1999). The characteristics of small size, great colonization ability, precocious maturation, continuous parceled reproduction and small number of offspring of Oligosarcus hepsetus fit the opportunistic strategy proposed by Winemiller (1989).…”

“…According to Vazzoler (1996), most Neotropical species display periodicity in their reproductive process, beginning their gonadal development during a period prior to reproduction and completing their gonadal maturation at such time as the environmental conditions are optimal for fecundation and for the development of their offspring, which is associated with the availability of food for their larvae (Bagenal, 1971).…”

Rétention Des Ovules Après Ovulation Dans La Cavité Ovarienne De La Carpe Herbivore : Composition Des Ovules Et Capacité De Développement Des Œufs Et Des Alevins.

“…On n'a pas relevé l'âge exact des femelles mais il s'est avéré lors de cette étude que le poids des femelles conditionne la viabilité post ovulatoire des ovules à partir de 90 minutes de rétention in ovario. En effet, la qualité des oeufs des poissons est considérablement affectée par l'âge et le poids des géniteurs (BAGENAL, 1971 ;KAMLER, 1976 ;KUZNETSOV et KHALITOV, 1979 ;PARRISH et al, 1995PARRISH et al, , 1996EVANS et al, 1996). Donc, ces facteurs maternels pourraient être mis en cause dans la disparité de la qualité et de la viabilité post ovulatoire des ovules observées au cours de nos expériences ; les femelles manipulées produiraient alors des ovules qui seraient biochimiquement différents.…”