Marine Oligochaeta from the Koster Area, West Coast of Sweden, with Descriptions of Two New Enchytraeid Species

Abstract

A total of 28 species of marine Oligochaeta (belonging to the families Naididae, Tubificidae and Enchytraeidae) are reported from eulittoral and sublittoral sediment samples taken in the Koster area on the Swedish West Coast. Lumbricillus algensis sp.n. and Grania ovitheca sp.n. are described and their morphological and taxonomical relations to other enchytraeids are discussed. L. algensis is characterized mainly by its spermathecae, which project into segment VI, and by its very large penial bulbs. G. ovitheca possesses no dorsal setae, the ventral setae being present posterior to the clitellum only, and its spermathecae consist of a narrow duct and a large egg‐shaped to oval ampulla, filling most of the coelom of segment V. Four sublittoral species, Limnodriloides barnardi (Tubificidae), Lumbricillus semifuscus, Marionina sublitoralis and Grania roscoffensis (all Enchytraeidae) are reported as new to the Swedish fauna.

Genetic variation and phylogeny of Scandinavian species of Grania (Annelida: Clitellata: Enchytraeidae), with the discovery of a cryptic species

“…The shape of its chaetae (entally thicker with a prominent heel and broad instep) (Fig. 3a) is similar to what has previously been reported in these two species (Rota and Erséus 2003: Fig 10B; Erséus 1977). The elongate chaetal foot with a curved sole is slightly more similar to that of G. ovitheca .…”

“…The elongate chaetal foot with a curved sole is slightly more similar to that of G. ovitheca . The chaetae of G. occulta are apparently slightly longer than the ones of G. ovitheca ; the longest chaeta ever reported in G. ovitheca was 68 μm (Rota and Erséus 2003) and in the type material, the size range was 50–65 μm according to Erséus (1977). In G. occulta, the size range is from 65 to 80 μm.…”

“…Grania postclitellochaeta , however, does possess ventral lobes in IV. The spermathecae of G. occulta are identical to the ones of G. ovitheca , with egg‐shaped ampullae deeply incised by the ectal ducts, containing numerous small sperm rings (Erséus 1977) and lateral spermathecal pores at a distance from 4/5 (Rota and Erséus 2003). The sperm funnels are very long, as originally described in G. ovitheca (Erséus 1977), and their collars are directed posteriorly.…”

“…Morphological identification of individual species, however, is complicated: it is necessary to stain, clear and mount specimens on microscope slides, as the commonly used characters are the details of the internal sexual organs and of the morphology and arrangement of the chaetae. Based on this, six species have been recognized from the coasts of Scandinavia: G. maricola Southern, 1913; G. pusilla Erséus, 1974; G. postclitellochaeta (Knöllner, 1935), G. variochaeta Erséus and Lasserre, 1976; G. ovitheca Erséus, 1977 and G. vikinga Rota and Erséus, 2003 (the last‐mentioned taxon was initially identified as G. roscoffensis Lasserre, 1967; see Erséus 1977). Most of these species have distributions that range from the west coast of Norway in the north, to outside of and sometimes inside the Mediterranean Sea in the south (Rota and Erséus 2003).…”

Taxonomy of North European Lumbricillus (Clitellata, Enchytraeidae)

“…Previously described from Denmark, Norway (Nurminen 1965b) the United Kingdom and Sweden (Erséus 1977). BIN-number: BOLD:AAU1636.…”