Reproductive capability of non-indigenous species introduced in Gran Canaria associated to oil platforms

Abstract

Introductions of non-indigenous species have generated serious alterations in the composition and function of ecological communities world-wide, giving rise to an important economic impact. The spread of a non-native species in a new region depends on various factors, mainly its tolerance to environmental conditions in the new ecosystem. These environmental conditions, especially temperature, have a great influence on the reproductive capacity of these species, affecting the maturity process, spawning, and the survival of offspring. To verify the reproductive capacity of the introduced non-native species associated with the oil platforms, under the environmental conditions found in the Canary Islands, was performed the capture of individuals of non-indigenous species by volunteer observers (Scuba divers, professional and recreational fishermen) in the Port of Las Palmas, and in areas of the marine Net Natura 2000 of Gran Canaria and were examined histologically. The specimens examined belonged to families Acanthuridae: Acanthurus bahianus (Castelnau, 1855), Acanthurus chirurgus (Bloch, 1787) Acanthurus monroviae (Steindachner, 1876); Serranidea: Cephalopholis taeniops (Valenciennes, 1828), Paranthias furcifer (Valenciennes, 1828); Pomacentridae: Abudefduf hoefleri (Steindachner, 1881); and Pomacanthidae: Pomacanthus paru (Bloch, 1787). These species have their native distribution range in tropical or subtropical regions as Brazil or Gulf of Guinea. All individuals examined of alien species were sexually immature or inactive, indicating that these species, at the moment, are not able to spread and increase their populations in Gran Canaria waters, with the exception of Cephalopholis taeniops, a hermaphrodite species, which was the unique with developed gonads.