Harpacticoida

Alper, Alp, 2022, Faunistic and ecological assessment of interstitial Harpacticoida (Crustacea, Copepoda) on a sandy beach in Balıkesir (Turkey), Nauplius (e 2022022) 30, pp. 1-14 : 10-11

Harpacticoida diversity

Harpacticoid copepod diversity on sandy beaches is inf luenced by many ecological parameters. This is probably the main driver determining the differences in harpacticoid species composition and abundances observed in different beaches. For example, Wells (1961) reported 55 interstitial harpacticoid species from the Isles of Scilly ( England). Harris (1972) determined 13 species from Whitsand Bay ( England) within a 2-year period. Mielke (1975) reported 61 species from Sylt( Germany).Thirty seven harpacticoid species were identified by Moore (1979) from 6 beaches on the Isle of Man ( England). Sixty species were reported by Mielke (1984) from beaches of the Galapagos Islands. Bodin and Jackson (1989) studied 6 beaches in Galway Bay ( Ireland) and Northern Brittany ( France), as a result a total of 85 species were recorded. George and Rose (2004) sampled monthly the shore of Chiloé Island ( Chile) between 1993 and 1994, and surprisingly only 1 harpacticoid species ( Sextonis mehuinensis (Mielke, 1985)) was reported; in terms of harpacticoid diversity, this was the first study reporting a monospecific beach. Two beaches on the Island of Crete ( Greece) (Elafonisi and Pahia Ammos) were studied for 13 months by Sevastou et al. (2011), and as a result a total of 96 species were reported (67 and 64 for Elafonisi and Pahia Ammos, respectively). Comparing the faunistic results of this study with the literature summarized above, species richness of Harpacticoida is high in Sarımsaklı beach, where a total of 66 species was collected. Three species identified in this study ( Arenosetella germanica Kunz, 1937 , Klieonychocamptus kliei , and Delamarella obscura Huys, Karaytug and Cottarelli, 2005 ) were reported previously by Karaytuğ and Sak (2006), so the remaining 63 species are new records for the beach. One family ( Cylindropsyllidae ), with 8 genera ( Proameira Lang, 1944 , Sicameira Klie, 1950 , Stenocaris G.O. Sars, 1909 , Minervella Cottarelli and Venanzetti, 1989 , Schizothrix Huys, 1992 , Protopsammotopa Geddes, 1968 , Wellsopsyllus Kunz, 1981 , and Karllangia Noodt, 1964 ) and 20 species are also new records for the Turkish marine harpacticoid fauna( Tab.4). Pseudamphiascopsis attenuatus orientalis Noodt, 1955 is reported for only the second time from Turkish seas since its description from the Sea of Marmara by Noodt (1955).

Ecological indices

Shannon’s H’ was calculated between 0.64 and 1.06 across the stations( Tab. 5). Although the total species diversity of the beach was high, the stations generally had low H’ values. Pielou’s J was calculated between 0.5 and 0.81 across the stations ( Tab. 5). Low values of H’ and J in a region indicate that species richness was imbalanced and the community was dominated by few species ( Magurran, 2004; Kiernan, 2014). In this study, the genera Ectinosoma Boeck, 1865 , Sarsamphiascus Huys, 2009 , Leptomesochra G.O. Sars, 1911 , and Ameira Boeck, 1865 were common and abundant throughout the studied period ( Tab. 4). Due to the dominance of these taxa, J values were lower than 0.7 at all stations except ST3, which had the highest evenness of 0.81. Means of both species richness and abundance at ST3 were lower than in most of the other stations ( Tab. 4; Fig. 4 ); however, the abundance of each species at this station was more equally distributed than at other stations.

Figures

Figure 4. The seasonal variation in the mean abundance (ind./7.5 cm2) of the harpacticoids at the stations.