Search results for " habitat selection"

Corynosoma cetaceum in the stomach of Franciscanas, pontoporia blainvillei (Cetacea): an exceptional case of habitat selection by an Acanthocephalan

2001

Adult acanthocephalans are typically found in the intestine of vertebrates, where they can readily absorb nutrients. However, Corynosoma cetaceum has been frequently reported in the stomach of cetaceans from the Southern Hemisphere. The ecological significance of this habitat was investigated by examining data on number, sex ratio, maturity status, biomass, and fecundity of C. cetaceum in different parts of the digestive tract of 44 franciscanas Pontoporia blainvillei. Individual C. cetaceum occurred in the pyloric stomach (PS) and, to lesser degrees, in the duodenal ampulla (DA) and the main stomach (MS). Females outnumbered males in all chambers, although the sex ratio was closer to 1:1 i…

First estimates of density and distribution of the alien crab Percnon gibbesi (Decapoda, Percnidae) in the "Capo Gallo-Isola delle Femmine" MPA

2013

Substratum recognition as settlement cue for larvae of Dendropoma cristatum (Biondi, 1859)

2017

Despite the ecological relevance of the vermetid bioconstructions in the Mediterranean, little is known about the early life stage of Dendropoma cristatum. This study describes the preference for settlement substrata from D. cristatumlarvae. A field experiment was carried out to test the suitability of crustose coralline algae (CCA), D. cristatumadults and two inorganic substrata as settlement surfaces. The number of settling larvae varied among the four treatments with higher settlement success on organic surfaces. CCA and D. cristatumindividuals seem to promote attachment of young larvae and to induce the metamorphosis in recruits. This is probably due to biological or physical properties…

Settlement dynamics and recruitment responses of Mediterranean gorgonians larvae to different crustose coralline algae species

2020

International audience; Sessile marine species such as Anthozoans act as ecosystem engineers due to their three-dimensional structure. Gorgonians, in particular, can form dense underwater forests that give shelter to other species increasing local biodiversity. In the last decades, several Mediterranean gorgonian populations have been affected by natural and anthropogenic impacts which drastically reduced their size. However, some species showed unexpected resilience, mainly due to the supply of new individuals. To understand the mechanisms underlying recovery processes, studies on the first life history stages (i.e. larval dispersal, settlement and recruitment) are needed. In tropical cora…

Hiding behaviour ofOxynoe olivacea(Mollusca: Opisthobranchia: Sacoglossa) in the invasive seaweedCaulerpa taxifolia

2013

The occurrence of the invasive seaweed Caulerpa taxifolia in the Straits of Messina (Italy) provides an excellent opportunity to examine the spatial and temporal patterns of abundance of the endemic Mediterranean sacoglossan Oxynoe olivacea. Densities of this species were recorded in March, June and October 2000 on three different habitats: the underside of boulders (UNB), the upper side of boulders (UPB), and the surface of concrete blocks (CB). Results showed that in March, O. olivacea was consistently more abundant on UNB whereas in June it was present exclusively on CB. The density of O. olivacea was similar in the three habitats in October. The hiding behaviour of O. olivacea and its s…