ANNALES • Ser. hist. nat. • 10 • 2000 • 1 (19) review article UD C 574 MEIOBENTHiC HARPACTiCOiDA (COPEPODA) FROM Tl iE SOUTHERN PART OF THE GULF OF TRIESTE (NORTHERN ADRIATIC) I. LIST OF TAXA Borut VRIŠER National institute of Biology, Marine Biological Station, SÍ-6330 Piran, Fornače 41 ABSTRACT The article presents an integral systematic review of free -living nonparasitic meiobenthic harpacticoid copepods, arranged on the basis of the extensive material gathered during all the past investigation into this group in the area of the southern part of the Gulf of Trieste between 1970 and 2000. The emphasis is on the alphabetical and systematic survey, which includes a total of 130 species, and on morphological-taxonomic features presented with the taxonomic sketches of 62 species. Key words: Harpacticoida, Copepoda, Gulf of Trieste, fist of taxa ARPACTICOIDÍ (COPEPODA : HARPACTÍCOIDA) MEiOBENTONíC I DELLA PARTE MERiDIONALE DEL GOLF O DI TRIESTE (NOR D ADRIATICO) I. ELENCO DELLE SPECIE SINTESI L'articolo presenta una revisione sistemática integrale di copepodi arpacticoidi meiobentonici, non-parassiti e conducenti vita libera, ottenuta grazie a un ampio numero di ricerche su questo gruppo, effettuate nella parte meridionale del Golfo di Trieste tra /7 1970 ed il 2000. L'autore ha messo in evidenza sia la revisione alfabética e sistemática, che comprende 130 specie, sia le caratteristiche morfo-tassonomiche, schematiziaíe per 62 specie. Parole chiave: Harpacticoida, Copepoda, Golfo di Trieste, elenco delle specie INTRODUCTIO N group of meiofauna, while the biocenotic and ecologi­ cal aspects of the so far made investigations in respect of The present contribution is an attempt, at the very the harpacticoids of this part of the Gulf are presented in first intégrai systematic review of meiobenthic, non-a separate article (VriSer, 2000). parasitic, free-living species of harpacticoids of the The aim of this contribution is to present a refined southern part of the Guif of Trieste, which predomi-and fairiy rounded up list of species supported with the nantly belong to the territorial waters of the Republic of author's SO far unpublished morphological-taxonomic Slovenia. The emphasis is on the list of species and on sketches (Figs. 1-9). As such it should be a basic aid to the morphological-taxonomic characteristics of the all future investigators of harpacticoids in our as well as more common species of this second most important a wider area. Borut VRISER: MFIOBENTHI C HARPACTICOID A (COPEPODA ) FRO M THE SOUTHER N PART .... 23-38 METHODS Ali samplings were carried out with the gravity core (Meischner & Rumohr, 1974) with the 10 cm2 aperture, some 5-10 cm deep into the sediment, mostly in three replicates; the meiofauna was extracted with the shak­ing-supernatant technique of Wieser (1960) and sieved through 0.125 mm and 0.050 mm sieves. During the determination of species and the revision of nomencla­ture w e relied mainly on the basic, taxonomic literature (Lang, 1948; Bodin, 1979) and on various taxonomic periodic sources, of which only a restricted selection is referred to in this article. ECOLOGICAL CHARACTERISTICS OF THE AREA All the samplings of harpacticoids carried out so far in the southern part of the Gulf of Trieste covered the entire depth range of these waters: from 1-15 m during the study of copepods of coastal profiles to the investi­gations of the open waters of the Gulf (19-25 m, and exceptionally 30 m depths). The coastal harpacticoids (1-15 m in the Bays of Koper, Strunjan and Piran) were studied comparatively during the summer and winter months, while the fauna of the deeper open waters was investigated only during the summer. Thermal condi­tions of the entire area oscillated between 9-21 °C , aver­age salinity was 37.5 PSU, oxygen content from 55 to 96 % saturation and only exceptionally below 40 % (at the time of hypoxic crises). The harpacticoids dealt with during the two coastal ecological studies (Marcotte, 1974; Vrišer, 1986) were only at two of their shallowest sampling localities (in the Koper and Piran Bays at depths ranging from 1-5 m) under the strong influence of organic pollution of urban origin, while the remaining Copepoda fauna that is dealt with by this article belonged to a clean, unpolluted en­vironment. The substrate of the investigated area is in view of its geological structure clayey silt (with 10-20% of clay), which on the coast turns into silty clays (with up to 25 % of clay), while in direction of the open sea it turns into fine sand (Ogorelec eta/., 1991). THE EXTENT OF RESEARCH INTO HARPACTICOIDS OF THE SOUTHERN PART OF THE GULF OF TRIESTE The first "pathfinding" investigations in the area were carried out by Marcotte during 1971-1972 within the framework of a comparative summer-winter study of the impacts of pollution on meiofauna of the coastal belt of the Piran Bay. From the depth transects of five localities ranging between 1 and 15 m, this research brought forth 53 harpacticoid species, 10 of which were not fully de­termined (Marcotte, 1973, 1974; Marcotte & Coull, 1974). Some meiofauna! samples were taken by the two Bulgarian copepodologists at 15 m near Piran in August 1971. In the published results of this study 25 species are treated (Marinov & Apostoiov, 1981a, b). On the basis of Marcotte's studies the author of this article carried out, in 1978-1979, a more extensive comparative summer-winter (February - August) eco­logical study of meiofauna (between 1 and 15 m) of the Piran and Strunjan Bays and in the polluted part of the Koper Bay. These investigations (Vriser, 1982, 1983, 1986) have rendered 62 harpacticoid species, 25 of which were eventually determined by Trajan Petkovski, the Macedonian expert for this group, and the rest by the author himself, 28 of them fully and 9 only partially. Morphological sketches of this material are fully pre­sented in this article (Figs. 1 -10). An extensive research into meiofauna of the entire area of Slovenian waters was carried out in August 1985 at 31 stations at depths ranging from 19 - 25 m (Vn'Ser, 1992). A survey of the entire collected material (almost 16000 harpacticoid individuals) has from this source rendered a total of 71 species. 34 of these have not been fully determined as yet. Within the framework of research into seasonal and long-term changes in meiofauna occurring in the envi­ronment frequently affected by hypoxia, a total of 42 harpacticoid species were determined between 1992 and 1995 at the research station in the centre of the Gulf of Trieste (VriSer, 1996, 1997), while the experiment on recolonization of artificially defaunated sediment during 1993-1995 at the experimental station off Piran (21 m) brought forth 32 harpacticoid species (Vriser & Vukovii, 1999). In this article, a full list of all until now registered harpacticoid species of the research area is presented for the very first time. It has been made on the basis of all studies carried out to date and covers a total of 130 species, in 35 of which only their genus has been de­termined. The number of species greatly surpasses the original expectations as well as estimates by some co­pepodologists (e.g. B.M. Marcotte, B.C. Coull & M. Specchi, pers. comm.) about the possible species di­versity of this group in our waters. i believe that the actual number of harpacticoid species of the investigated area, i.e. in nature, is most probably not much greater than 150, although some of the present-day species determinations might well be refuted by future investigations. Considering the number of species, the harpacticoid fauna of the Gulf of Trieste can be assessed as a medium diverse area, if compared with the studies of spatially much larger areas in the Mediterranean: 340 species on the entire Cote d'Azur (Chappuis, 1953), 164 in the Eastern Mediterranean, 140 along the Israeli coast, 121 in the Black Sea (Por, 1964), 250 along the Catalonian coast (Soyer, 1970), etc. In spite of the exceptional abundance of specimens ANNALE S • Ser. hist. nat. • 10 • 2000 • 1 (19) Sorul VRIÍER ; MEIOBENTHI C HARPACTiCOIDA (COf'EPODA) FRO M THE SOUTHER N PART .... 23-38 from the research carried out so far, the determination of 18. Amphiascus spA the greater part of the incompletely determined species 19. (M) Asellopsis spA has been rendered difficult due to the fact that only a 20. Bradya (Bradya) typica Boeck, 1872 few individuals have been found together, although 21. (M) Buibamphiascus imus (Brady, 1872) quite often at more than just a single locality. In spite of 22. (M) Buibamphiascus inermis (SewelI, 1940) a series of difficulties (e.g. a high share of juvenile indi-23. Buibamphiascus minutus (Dlnet, 1971) viduals, unfavourable sex structure, injured individuals, 24. Buibamphiascus sp.?.. ecological variability of taxonomic features, etc.I this 25. Brianola stebleri (Monard, 1926) still enabled to make a distinction among separate spe-26. (M) Canuella furcigera Sars, 1903 cies, but certainly not their positive determination. So-27. (M) Canuella perplexa T. & A. Scott, 1893 lution of such individual problems - some of the species 28. Canuella sp.1 may even be new to science - is extremely time-con-29. (M) Cletodes pusillus Sars, 1920 suming, for a renewed search for these species demands 30. (M) Cletodes iimicola Brady, 1872 specific repeated samplings which, however, are not 31. Cletodes longicaudatus Boeck, 1872 necessary successful at all times. These problems thus 32. Cletodes tenuipes Brady, 1896 remain a goal and the subject of the future research. 33. (M) D'Arcythompsonia scotti Gurney, 1920 In spite of the many studies carried out in the past, 34. D'Arcythompsonia sp1 the knowledge of the Adriatic harpacticoids is today still 35. Dactylopodella flava (Claus, 1866) rather modest. The extent of research into this group in 36. (M) Dactylopodia tisboides (Claus, 1863) the Slovene waters is a considerable exception, for in 37. Danielssenia perezi Monard, 1935 the Mediterranean, too, it is very difficult to find a com-38. (M) Diagoniceps menaiensis Geddes, 1968d parable small area, where so much harpacticoid re-39. Diarthrodes minutus (Claus, 1863) search has been carried out to date. 40. (M) Diosaccus tenuic.ornis (Claus, 1863) 41. Diosaccus sp. 1 LIST O F TAXA 42. (M) Ectinosoma normani T. & A. Scott, 1894a 43. (M) Ectinosoma obtusum Sars, 1920 The list includes all till now registered and identified 44. (M) Ectinosoma dentatum Steuer, 1940 harpacticoid species of the Slovene part of the Gulf of 45. Ectinosoma melaniceps Boeck, 1864 Trieste. For utterly practical reasons, particularly in order 46. Ectinosoma sp.1 to make the search easier, the species are arranged in 47. Ectinosoma sp.2 alphabetical order. Separate incompletely determined 48. (M) Enhydrosoma buchholtzi (Boeck, 1872) species are marked Genus sp. and numbered. 49. (M) Enhydrosoma caeni Raibaut, 1965 The letter (M) by the consecutive number before the 50. Enhydrosoma longifurcatum Sars, 1909 names of genus and species indicates that the species 51. (M) Enhydrosoma sordidum Monard, 1926b under the same number is also presented with a sketch 52. (M) Enhydrosoma propinquum (Brady, 1880) of the morphological-iaxonomic features (see the follow-53. Enhydrosoma tunisensis Monard, 1935a ing chapter: morphological characteristics and taxo-54. (M) Enhydrosomella staufferi Monard, 1935a nomic features of species). 55. (M) Esola longicauda Edwards, 1891 56. Eurycletodes (Oligocletodes) latus 1. (M) Acrenhydrosoma perplexum (T. Scott, 1899) (T. Scott, 1892) 2. (M) Ameira. parvula (Claus, 1866) 57. (M) Eurycletodes (Oligocletodes) spA 3. Ameira sp. 1 58. (M) Euterpina acutifrons (Dana, 1848) 4. Ameira sp. 2 59-Halectinosoma angulifrons (Sars, 1919) 5. Amonardia similis (Claus, 1866) 60. Harpacticus obscurus T. Scott, 1895b 6. (M) Amphiascoides debilis (Giesbrecht, 1881) 61. Harpacticus tenellus Sars, 1920 7. Amphiascoides próxima (T. Scott, 1914) 62. (M) Harpacticus spA 8. (M) Amphiascoides spA 63. (M) Harpacticus sp.2 9. Amphiascopsis thaiestroides (Sars, 1911) 64. Harpacticus sp.3 10. Amphiascopsis cinctus (Claus, 1927) 65. Harpacticus sp.4 11. (M) Amphiascopsis sp. 1 66. Harpacticus sp.5 12. Amphiascopsis sp. 2 67. Haloschizopera bulbifera (Sars, 1911) 13. Amphiascopsis sp.3 68. Haloschizopera junodi (Monard, 1935b) 14. Amphiascus caudaespinosus Brian, 1927 69. (M) Haloschizopera pontarchis Por, 1959 15. Amphiascus congenerSars, 1909 70. Haloschizopera spA 16. Amphiascus rninutus Claus, 1863 71. (M) Hemimesochra nixe Por, 1964 17. (M) Amphiascus varians Norman & T.Scott, 1 905 72. Hemimesochra spA Borut VRfSER: MEIOBENTHJ C HARPACTiCOiDA (COPEFODA) fRO M THE SOUTHER N PART .... 23-33 73. HeterolaophonteSeweII, 1924 74. (M) Helero!aophonteNoodí, 1955d 75. (M) Heterolaophonte quinquispinosa stroemi paramínuta spA 76. (M) Heteropsyllus curticaudatus T. Scott, 1894a 77. Heteropsyllus sp.'l 78. (M) Horsiella sp. 1 79. Itunella muelleri(Gagern, 1922) 80. Laophonte longicaudata Boeck, 1864 81. (M) Laophonte sima Gurney, 1927 82. (M) Laophonte inornata A. Scott, 1902 83. (M) Laophonte cornuta Philippi, 1840 84. Laophonte spA 85. Laophonte sp.2 86. Laophonte sp.3 87. Laophonte spA 88.