Lanna, E.; Paranhos, R.; Paiva, P.C.; Klautau, M. (2015). Environmental effects on the reproduction and fecundity of the introduced calcareous sponge Paraleucilla magna in Rio de Janeiro, Brazil. Marine Ecology. 36(4): 1075-1087.
Environmental effects on the reproduction and fecundity of the introduced calcareous sponge <i>Paraleucilla magna</i> in Rio de Janeiro, Brazil
Marine Ecology
36(4): 1075-1087
Publication
Available for editors
The calcareous sponge Paraleucilla magna (Porifera, Calcarea) has been the sub?ject of several studies in the last decade. It was first described along the Brazilian
coast, where it is considered cryptogenic, and was subsequently found in the
Mediterranean, where it is considered invasive. The wide artificial distribution of
this species allows us to compare different aspects of the biology of an introduced
species in different locations. Here, we analysed the effects of selected environ?mental parameters on the reproductive dynamics of P. magna in Rio de Janeiro (Brazil) over 18 months and compared our results with those obtained for the same species in the Mediterranean Sea. Specimens were collected monthly and analysed through histological methods. The density of reproductive elements in each month was calculated, and the effects of environmental parameters (photoperiod, precipitation, temperature, phytoplankton and bacterioplankton) were analysed using a regression tree analysis. Paraleucilla magna was reproductive throughout the study period. The densities of the reproductive elements (oocytes, embryos and larvae) showed no seasonality, and this species presented one of the highest reproductive efforts documented to date in the phylum Porifera (99.0 oocytes ? mm?3 ; 89.0 embryos ? mm?3 ; 319.0 larvae ? mm?3). The main environmental parameters related to the reproduction of P. magna were temperature, photoperiod and bacterioplankton. Temperature was the main driver associated with the densities of oocytes and embryos, while bacterioplankton was the main driver of larvae (positive relationships). In Rio de Janeiro, larvae were present
and continuously released. This strategy is different from that observed in the Mediterranean, where a larger larval output was observed but only during the summer months. Our results show that P. magna is a species with a strong invasive potential, considering its high and continuous reproductive effort. This high fecundity stimulated by high temperatures may be a key factor contributing to the growth of P. magna populations and its invasion of new areas
South West Atlantic ( =only warm temperate; cold temperate see *SUB)
