Amphipod colonization patterns on artificial seagrass substrata: contrasting differences between the day and the night through a lunar cycle. P-G-GO-ZALEZ L., ...
! ORAL PRESENTATION Amphipod colonization patterns on artificial seagrass substrata: contrasting differences between the day and the night through a lunar cycle. PNG-GONZALEZ L., GARCêA-SANZ S., TUYA F. Department of Biology, Marine Sciences Faculty, Universidad de Las Palmas de Gran Canaria, Canary Islands, Spain
Amphipods, as many other epifaunal organisms living on seagrass meadows, colonize new habitats through active swimming or being transported passively by water movement. In this study, we took advantage of Artificial Seagrass Units (ASUs) to test whether the intensity of invertebrate colonization on a seagrass meadow differs between the day and the night through a complete lunar cycle. ASUs were deployed, and subsequently retrieved, during the day (between 9:00 a.m. and 18:00 p.m.) and the nighttime (18:00 p.m. and 9:00 a.m.), at three consecutive days within each of four successive moon phases (7-9 m depth). A total of 13872 amphipods were collected. Larger abundances and species density of colonizing amphipods were obtained at the night than the day. Significant differences in the number of amphipods among moon phases were additionally observed: larger abundances of amphipods were registered during the full moon, while the lowest abundances were observed in the first quarter phase. Regarding to the composition of the amphipod assemblage, different species were found between the day and the night, according to their ecological habits. In particular, larger abundances of Apherusa sp. and Dexamine spinosa were observed during the night relative to the day (2-3 times).