Loimia Malmgren, 1866

Carrerette, Orlemir & Nogueira, João Miguel De Matos, 2015, The genus Loimia Malmgren, 1866 (Annelida: Terebellidae) off the Brazilian coast, with description of three new species and notes on some morphological characters of the genus, Zootaxa 3999 (1), pp. 1-31 : 3

Genus Loimia Malmgren, 1866

Type species. Terebella medusa Savigny in Lamark, 1818

Diagnosis. Eyespots sometimes present at prostomium. Lobes present on segments 1 and 3, sometimes also on segment 4; lobes of segment 1 beginning dorso- to ventro-laterally, extending across ventrum; lobes of segment 3 inserted lateral to ventro-laterally. Three pairs of branching branchiae, on segments 2–4. Glandular shields present from segments 2–3 through segments 12–16. Seventeen pairs of notopodia beginning from segment 4, bearing narrowly-winged notochaetae. Neuropodia beginning from segment 5, bearing pectinate uncini throughout; uncini in double rows on segments 11–20, rows with uncini in back-to-back to crest-to-crest arrangement. Genital papillae on segments 6–8.

Remarks. Loimia has a confused taxonomic history, with several taxa mistakenly reported worldwide. The most useful morphological characters to identify the species within this genus are: (1) shape and position of the lobes on segments 1 and 3; (2) shape of ventral glandular shields and number of segments on which they are present; (3) number of uncinial teeth (from both anterior and posterior regions) as well as the general morphology of the uncini, including presence of processes and filaments ( Hutchings & Glasby 1988, 1995; Hutchings 1997; Londoño-Mesa and Carrera-Parra 2005; Londoño-Mesa 2009).

We agree with Hutchings and Glasby (1988, 1995) and Londoño-Mesa (2009) regarding the critical importance of the morphology of anterior lobes and uncini, but we have herein recognized additional characters which are useful to distinguish between species of Loimia , or at least for those occurring off the Brazilian coast. The presence of eyespots and their size, for example, should also be considered in species descriptions, as well as the number, arrangement and shape of mid-ventral glandular shields, as discussed below.