Abstract: | Parental care may be defined as an association between one or both parents and the young, association increasing the survival chances of the latter (Sargent & Gross, 1986). Among the vertebrates, mammals show a parental care exclusively maternal in 90 % of the families and a biparental care in 10% of the families. There are no mammal species in which only the male takes care of the young. Among the birds, in 90 % of the cases both parents care for the brood and the chicks, in 8% only the female cares for them and in only 2 % the males are taking care alone for the young.
Among the fish, the majority of the species show any parental care for the fry, however among the species that do (approximately 20% of the families) the majority present exclusively paternal care (50% of the cases) followed by an exclusively maternal care (30% of the cases) and biparental care (20% of the cases) (Gross, 2005).
Unlike other vertebrates, fishes continue to grow in size and, implicitly, in weight after they reach sexual maturity. At fish, both female fecundity and the number of eggs fecundated by the male tend to increase with the body size. The energy spent with the reproduction directly affects the growth; this is why the reproductive future of a fish depends on how much it invests in its growth and how big it gets in body size and weight (Sargent & Gross, op. cit.).
At fish species with an exclusive male caring of the brood and fry, it is known the fact that the males loose weight especially during the period they occupy and defend a territory. As a rule, after the breeding period, there is a high mortality as was noticed at the species Lepomis gibbosus (Gross, 1980). |
