Vertical distribution of protozoan and microcopepod communities in the South Adriatic Pit

• Published in: Journal of plankton research Vol. 20; no. 6; pp. 1033 - 1060
• Main Author: KRSINIC, F
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 1998
• Subjects: Adriatic Sea; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Sea water ecosystems; Synecology; Mediterranean Sea; Adriatic Sea; MED, Adriatic Sea; Community structure; Protozoa; Vertical distribution; Bathymetry; Actinopoda; Crustacea; Marine environment; Species diversity; Submarine trench; Faunal survey; Animal community; Arthropoda; Copepoda; Population dynamics; Radiolaria; Invertebrata; Zooplankton; Population density
• ISSN: 0142-7873; 1464-3774
• DOI: 10.1093/plankt/20.6.1033

The qualitative composition, numerical abundance and vertical distribution of radiolarians, tintinnines, nauplii and small copepod assemblages were studied in the central area of the Southern Adriatic Pit at three stations during 10 cruises from October 1985 to May 1990. The samples were collected with a plankton net of 53 μm mesh size equipped with a closing system in eight vertical layers. Data are presented for 53 radiolarians, 61tintinnines and for the first time for 22 poecilostomatoid species in the Adriatic Sea. According to the numerical abundance of assemblages and the frequency of occurrence of the bulk of the individual species population in the water column, four communities could be defined: the surface (0–50 m), the subsurface (50–100m), the midwater (100–600 m) and the deep-sea community (below 600 m). The euphotic layer was characterized by tintinnines, copepod nauplii, cyclopoids and juvenile calanoid copepods, while radiolarians and poecilostomatoid copepods dominated in the deeper layers. The highest numerical differences between stations and seasons were noted only on the surface. Towards the deeper layers, the differences were constantly smaller, and below400 m there was a uniform distribution of all assemblages. This research, on the basis of the numerical abundance of protozoans and micrometazoans, shows that the central part of the South Adriatic Pit is considerably richer than mentioned by earlier authors.