Depressiscala nautlae ( Mörch, 1875 )

Simone, Luiz Ricardo L., 2024, New species, misidentifications and problematic taxonomy of some Atlantic South American marine mollusks: a review, Papéis Avulsos de Zoologia 64, pp. 1-104 : 12

Depressiscala nautlae ( Mörch, 1875) ( Fig. 7 A-F)

Scala nautlae Mörch, 1875: 265 .

Scala scipio Dall, 1889: 27 , 310. Epitonium (Depressiscala) nautlae : Abbott, 1974: 122 (fig.1271); Rios,1975:56 (pl.15,fig.217),1994:157(pl.52, fig.743), 1994:99 (pl. 32,fig. 400),2009:181 (fig.439).

Depressiscala nautlae : Rosenberg et al., 2009: 641.

Type localities: S.nautlae : ad litus mexicanum inter Vera Cruz et Nautla. Scala scipio : Vera Cruz; sta. 2597, 20 miles SW by S from Cape Hattenas, N.C., 15 + 12 fms.

Remarks: Specimens found on the Brazilian coast with the shell characteristics shown in Fig. 7 A-C were identified as both D. nautlae and D. niditella ( Dall, 1889) . A comparison to the lectotype of D. nitidella (USNM 83716) ( Fig. 7G ) reveals that they do not belong to that species, as the shells are much slenderer and lack an umbilicus. Conversely, their shells are virtually identical to the lectotype of Scala scipio ( Fig. 7D, E ), a species presently considered synonymous with D. nautlae .

The issue arises from the apparent existence of two different morphs under this epithet. One resembles the S. scipio model, with a deeper suture, more distant and narrower axial threads, and always with an amputated apex ( Fig. 7 A-E). The other morph, illustrated in Fig. 7F , features a shallower suture, taller and more closely locat- ed axial threads, and a complete apex. This latter morph is illustrated, for example, in Abbott (1974). Upon analyzing these specimens, the most parsimonious conclusion is that they belong to different species. However, it is important to determine whether the types of Mörch (1875) resemble them, as they have not been located or photographed to the best of our knowledge. This is an important issue for future surveys.

Material examined: USA. Florida ; Pompano Beach, 52 m, ANSP 457201 , 2 shells (Harriet, Robertson & Golberg col., 2004) . BRAZIL. São Paulo ; Ubatuba, praia Puruba , 23°21′09.2″S 44°55′54.3″W, MZSP 166500 , 1 shell, 165694, 7 shells (D. Forcelli col., viii.2023). Plus 11 lots of MZSP collection from Piauí to São Paulo .

Figures

Figure 7. Depressiscala nautlae and D. nitidella shells: (A-B) D. nautlae, MZSP 166500, from Ubatuba, São Paulo, Brazil (L 14.0 mm), frontal and dorsal views; (C) same, MZSP 165694, same locality (L 13.1 mm); (D-E) Lectotype of Scala scipio USNM 10694 (L 14.9 mm); (F) D. nautlae (L 13.3 mm), ordinary specimen from Pompano Beach,Florida,ANSP 457201, frontal view;(G) Scala nitidella, lectotypeUSNM 83716 (L 13.1 mm), frontal view (USNM photos courtesy Ellen Strong).