Exploring Benthic Scavenger Assemblages, a Multi-Habitat Approach in NW Iberian Peninsula

Abstract

Scavenging fauna plays an integral role in ecosystem functioning, nutrient cycling and circulating organic matter. Thus, baseline data of scavenger assemblages on the NW coast of the Iberian Peninsula that provides information on the abundance of species in different habitats is crucial to understanding the distribution of this understudied group. Two different types of baited traps, to capture scavenging megafaunal and scavenging benthopelagic macrofaunal assemblages, were deployed to compare them among rocky, pebbled and sandy bottoms at shallow subtidal on the northern coast of Portugal. Results showed significant differences in the structure of scavenger assemblages. Scavenging megafaunal assemblages differed between sandy and the other two studied habitats, whereas benthopelagic macrofaunal assemblages differed between pebbles and rocky habitats. This suggests that different drivers seem to shape the structure of benthopelagic macrofauna and megafauna. Regarding megafauna, the dominance of Tritia gastropods in sand habitats in comparison with its absence in rock and its very low abundance in pebbles was mainly responsible for the differences. However, in benthopelagic macrofauna, differences in assemblages between pebbles and rock were more related to changes in the relative abundance of crustacean species (Cirolana cranchii and Socarnes erythrophthalmus) that were less abundant in pebbles.

New occurrence of Cirolana capricornica (Isopoda: Cirolanidae) from Epinephelus chlorostigma in Suez Governorate, Egypt

“…Cirolana spp. has also been isolated from the ventral surface of deep-sea shark (Heptranchias perlo) from the Bahamas [26]. Finally, isopod scavenging has been reported in the coelomic cavity, on the external surface of organs (liver), and inside the esophagus and skull (salt gland) [2].…”

“…Bruce indicated that cirolanids are scavengers and predators that attach to fish from which they extract their nutrients and kill confined fishes [25]. Under favorable conditions, Cirolana fluviatilis becomes a serious pest and can cause mass mortality in cage-cultured finfish [26]. On the other hand, Keable considered Natatolana, one of the cirolanid species, as an opportunistic and voracious scavenger [27] because they usually swarm in large numbers and attack damaged fish, especially at dusk or during the night [28].…”