Taxonomic Status and Geographic Variation of the Marine Enchytraeid Genus Grania Southern (Oligochaeta)1

Abstract

Erséus, C. (Department of Zoology, University of Göteborg, S‐400 33 Göteborg, Sweden) and Lasserre, P. Taxonomic status and geographic variation of the marine enchytracid genus Grania Southern (Oligochaeta). Zool. Scr. 5 (3–4): 121–132, 1976.—New material from Europe, Bermuda and the eastern coast of North America allow more realistic determination of the generic characteristics of the marine enchytraeid genus Grania. This re‐evaluation of Grania necessitates the consideration of Hemigrania as a junior synonym, because of the now established absence of peptonephridia in Grania. Full enumeration of known localities shows the genus Grania to have a broad, disjunct distribution, low species number, and morphological conservatism. G. postclitellochaeta (Knöllner) and G. macrochaeta (Pierantoni) are considered as polytypic species, containing respectively two (including G. postclitellochaeta longiducta subsp.n.) and three (including G. macrochaeta bermudensis subsp.n.) subspecies. G. maricola Southern, G. roscoffensis Lasserre, G. vario‐chaeia sp.n. and G. monospermatheca sp.n. are considered as monotypic species.

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

“…It is worth noticing that species of Grania in other parts of the world also have reduced anterior chaetae. For example, G. eurystila Coates and Stacey, 1997; so far only known from Darwin harbour, Northern Australia, has the same chaetal distribution as G. postclitellochaeta (Coates and Stacey 1997), and, similarly, the North‐West Atlantic G. monospermatheca Erséus and Lasserre, 1976 (used here as outgroup), lacks all pre‐clitellar ventral chaetae, as well as lateral chaetae altogether (Erséus and Lasserre, 1976). With respect to both of these species, the species found in Scandinavia are a monophyletic group (De Wit et al., in prep), so it is clearly possible that this character has evolved convergently in several different lineages of Grania .…”

“…For outgroup comparison, the COI and ITS regions of one individual each of the species G. laxartus Locke and Coates, 1999 and G. monospermatheca Erséus and Lasserre, 1976; from Australia, Bahamas and Florida, respectively, which are likely to be close relatives of the Scandinavian species (De Wit et al., in prep), were also amplified and sequenced (Table S2).…”

“…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).…”

Global checklist of species of Grania (Clitellata: Enchytraeidae) with remarks on their geographic distribution

“…Erséus & Lasserre, 1976 Grania postclitellochaeta longiducta Erséus & Lasserre, 1976: 127, fig. 7, tab.…”

“…-Diaz et al 1987 12. Grania monospermatheca Erséus & Lasserre, 1976 Grania monospermatheca Erséus & Lasserre, 1976: 127, fig. 9, tab.…”