AxIOM: Amphipod crustaceans from insular Posidonia oceanica seagrass meadows

Study Extent

The dataset 187 sampling events, spanning 3 consecutive years. Sampling took place in two regions: Corsica (Calvi Bay) and Sardinia (Tavolara-Punta Coda Cavallo Marine Protected Area). To acknowledge temporal variation of communities, samples were taken during different periods of the year (November, March, June, July, August) and during both day and night. Sampling stations encompass various levels of environmental protection and anthropogenic pressure, including integral reserve, partial reserve, general reserve , unprotected pristine zone and heavily impacted zone.

Sampling

All sampling was performed by SCUBA diving at depths ranging from 10.4 to 15 metres. 4 complementary methods were used: hand-towed net, litter collection, air-lift and 2 slightly different types of light traps. In both investigated regions, a nested hierarchical sampling design was setup to fully capture the spatial variability of amphipod community structure over multiple scales spanning four orders of magnitude (1 to 1000 metres).

Quality Control

Sampling protocols were standardized to avoid biases. After identification, specimens were randomly selected to be re-examined by either first or last author in order to check identification accuracy. Species names were matched against the authoritative, expert-driven World Register of Marine Species (WoRMS).

Method steps

1. After collection, all samples were sieved on 400 µm nylon mesh to eliminate sediment and fine particulate organic matter. They were subsequently fixed for >24 hours in a formaldehyde solution (4% in 0.22 µm-filtered seawater). Samples were then sorted to isolate amphipods and transfer them to a preservation solution consisting of 70% ethanol in distilled water to which 1% glycerine was added to prevent evaporation. After identification, specimens were stored in this preservation solution in airtight vials.

This dataset comprises 72 amphipod species (including 2 subspecies of Caprella acanthifera) belonging to 51 genera and 29 families.

1. Animalia
   common name: Animals rank: kingdom
2. Arthropoda
   common name: Arthropods rank: phylum
3. Crustacea
   common name: Crustaceans rank: subphylum
4. Malacostraca
   rank: class
5. Eumalacostraca
   rank: subclass
6. Peracarida
   rank: superorder
7. Amphipoda
   common name: Amphipods rank: order

AxIOM contains samples taken in Posidonia oceanica seagrass meadows from Mediterranean Islands. Two regions were investigated: Corsica (Calvi Bay) and Sardinia (Tavolara-Punta Coda Cavallo marine protected area)