Botula Mörch, 1853

Kleemann, Karl, 2007, Catalogue and bibliography of Recent and fossil Botula (Bivalvia: Mytilidae), Zootaxa 1508, pp. 1-48 : 4

Botula Mörch, 1853

( Fig. 1 )

Type species. Modiola cinnamomea Lamarck, 1819 , subsequent designation by Dall (1898: 792). Wilson & Tait (1984: 113), although referring to Dall (1898), incorrectly noted Mytilus fuscus Gmelin, 1791 as type species (see Discussion).

Diagnosis. Shell somewhat ovate to kidney-shaped, smooth; umbones terminal, prominent, somewhat coiled; siphons separate. The anterior retractor is fastened on the anterior thickened margin of the shell just below the umbones. The posterior adductor is small and the posterior retractor leaves a small scar above the adductor ( Soot-Ryen 1955: text-fig. 70).

Remarks. Mörch (1853: 55) assigned to Lithophaga (Botula) three species: (1) Tamarindiformes arenaria Meuschen, 1787 , with Modiola vagina Lamarck, 1819 and M. castaneus Gray ( Rumphius 1705: pl. 46 fig. E) listed as synonyms, locality India Orientalis; (2) indet sp., no locality, and (3) L. (B.) fusca ( Gmelin, 1791) referring to Lister’s pl. 359 fig. 197, with Mytilus brunneus Solander, 1786 and Modiola cinnamomea var. Lamarck, 1819 and M. favannii Potiez & Michaud, 1844 listed as synonyms, locality Insulae Antillarum. Based on the subsequent type species designation ( Dall 1898: 792), only cinnamomea and fusca are members of Botula . The question remains, whether they are separate species or conspecific (see species problem).

Soot-Ryen (1969) considered Botula to belong to Modiolinae , although the genus does not fit to the general characters he lists for the subfamily: modioliform, beaks slightly behind anterior end, hinge margin smooth or finely striated vertically, shell surface usually lacking radial sculpture, periostracum commonly hairy, free-living, often nestling. Compared with Adula and Lithophaga , the proportions of the valves are relatively shorter and higher, the umbones inflated, the convex anterior and posterior dorsal margins thickened and crenulate in Botula ( Turner & Boss 1962) , but there are definitely no crenulations in Botula . The only ornament of the shells, if present, results from growth lines or steps ( Fig. 1 ).

Figures

FIGURE 1. Shell characters of boring mytilid genera Botula, Lithophaga, Adula, Gregariella, and of non-boring “ Notobotula ”. (a) left lateral view, (b) anterior view, (c) posterior view.