| Author Title Journal |
Kincaid ES, de Rivera CE (2021) Predators associated with marinas consume indigenous over non-indigenous ascidians. Estuaries and Coasts 44(3): 579-588 [doi: 10.1007/s12237-020-00793-2 goto] |
Abstract / Notes
"The establishment of non-indigenous species is influenced both by species traits and the biotic interactions that create resistance to or facilitate invasion. Predation, for example, creates resistance to non-indigenous ascidians in benthic habitats. Daytime surveys of fouling communities on floating docks in the Charleston Marina, Oregon, USA in August 2014 revealed that the indigenous ascidianDistapla occidentaliswas present at all sites and was being consumed by the flatwormEurylepta leopardaand the nudibranchHermissenda crassicornis.In contrast, the non-indigenousBotrylloides violaceusandBotryllus schlosseriwere present at fewer sites and lacked signs of predation. Parallel surveys in July 2015 again revealed predators found on docks were eating the indigenous ascidian. Examination of surrounding intertidal habitats revealed the dominant predators were the hermit crabPagurus granosimanusand shore crabHemigrapsus oregonensis, species not found in the marina fouling community. Feeding assays with the four predators and the ascidians showed that the flatworm specialized on the indigenousD. occidentalis, eating it almost 50 times faster than the NIS, which it did not consume. The nudibranch and shore crab mainly fed onD. occidentalisas well, consuming it two to four times faster than the NIS. In contrast, the benthic hermit crab mainly fed on the non-indigenous ascidian, feeding on it almost three times faster than it ateD. occidentalis. Hence, the non-indigenous ascidian likely faced reduced predation pressure in the marina fouling communities, increasing invasion risk. The study also examined several aspects of ascidian palatability, which showed that predator feeding was affected by differences in tunic structure. The study suggests that the different predators in the fouling and benthic communities in this marina have a role in the invasion of ascidians."| Home page -- (Main hierarchy) |