Crepidula glauca Say, 1822

Simone, Luiz Ricardo L., 2006, Morphological and phylogenetic study of the Western Atlantic Crepidula plana complex (Caenogastropoda, Calyptraeidae), with description of three new species from Brazil, Zootaxa 1112 (1), pp. 1-64 : 29-30

Crepidula glauca Say, 1822

(Figs. 19–21, 113, 123–125)

Synonymy see Simone (2002). Complement:

Crepidula convexa: Collin 2001 (figs. 2, 3); Simone 2002: 36–38 (figs. 8, 9, 66, 67, 152–159). [non Say, 1822]

The anatomical description by Simone (2002) is accurate. The shell is similar to C. margarita (Figs. 19–21). The single addition is the confirmation that the female genital papilla has smooth outer surface, lacking any kind of folds (Fig. 113).

The examined specimens have been erroneously identified as Crepidula convexa Say, 1822 in my previous paper ( Simone, 2002), which is here corrected. The change of the concept was based on the examination of voucher specimens at BMNH as explained following.

There are some samples of Crepidula convexa in the visited museums; however, coincidently few them have precise locality data. Voucher material of Reeve (1859) (BMNH 1829) has no locality at the label. Some samples (BMNH, ANSP 357830) show that the species occur in the north­western Atlantic, sometimes referred for estuary. The shell of C. convexa is very characteristic (Figs. 126–1295) in being small (about 10 mm), dark reddish colored, highly convex (tall for the genus) and with a projected posterior beak, keeping the protoconch away from substrate and normally distant from the posterior shell border (Fig. 127). The shell septum is weakly and centrally concave at its edge (Fig. 128). Additionally, a conspicuous feature is the large muscle scar present in right side, just dorsal to right septum insertion (Fig. 126). A sample with soft parts was examined (BMNH from New Jersey), revealing a huge dorsal muscle. These characters show that C. convexa is not actually close to the C. plana complex, and some distinctive anatomical attributes are present.

On the other hand, Crepidula glauca , which has been considered a form of C. convexa (e.g., Warmke & Abbott, 1961; Abbott, 1974), appears to be a separated species. This conclusion is based on the examination of voucher lot of Reeve (1859) (BMNH no locality) (Figs. 123–125). The shells are flat, wide, whitish, with apex fused with shell edge, sigmoid septum edge, and with the muscle scar shallow and small. These characters are common in the C. plana complex. In being the examined specimens virtually identical to the Reeves lot, the systematics of these species can be resolved, considering C. glauca a valid species, separated from C, convexa , possessing the shell and anatomical attributes described here and by Simone (2002).

Additional material examined: No locality, BMNH, 4 shells (voucher of Reeve, 1859). VENEZUELA; Isla Margarita, off Morro de Pto. Moreno, 13–17 m depth, ANSP 240085 , 1 dry specimen (Wesley M. Heilman leg. 16/ii/1959; sta. 28) .

Material examined of Crepidula convexa: No locality; BMNH 1829 , 4 shells (Voucher of Reeve, 1859); BMNH, 3 shells (Van Couvers Lsd); BMNH, 4 shells (figured specimen; H. Cuming collection). UNITED STATES OF AMERICA; Massachusetts; Plymouth , BMNH, 12 shells. Connecticut; Bridgeport , Fairfield county , Long Island sound, St. Marys estuary, 41º10N 73º10W, ANSP 357830 , 1 shell (Hoagland & Hoagland col. 1982). New York; Northport, BMNH 1838 , 9 shells (Winckworth colln.). New Jersey; Cape May, Wildwood, BMNH 20020070 , 6 specimens (R. Collin col. 13/vi/1999) .