Similiphora intermedia (C.B. Adams, 1850)

Fernandes, Maurício Romulo & Pimenta, Alexandre Dias, 2019, Basic anatomy of species of Triphoridae (Gastropoda, Triphoroidea) from Brazil, European Journal of Taxonomy 517, pp. 1-60 : 39-43

Similiphora intermedia (C.B. Adams, 1850)

Figs 2J , 25–27

Material examined

BRAZIL – Ceará State • [1] spec.; Praia da Pedra Rachada, Paracuru ; 16 May 2003; L.R. Simone leg.; MZSP 36450 . – Alagoas State • [1] spec.; Praia da Ponta Verde, Maceió ; 09°40´05″ S, 35°41´35″ W; 1 m depth; M.D. Correia leg.; MZSP 102113 . – Bahia State • [1] spec.; Forte Santa Maria, Salvador ; 13°00´15″ S, 38°32´03″ W, 0–10 m depth; 18 Feb. 2016; M.R. Fernandes leg.; MNRJ 35062 . – Espírito Santo State • [1] spec.; Ilha Escalvada, Guarapari ; 20°42´00″ S, 40°24´28″ W; 10–15 m depth; 12 Oct. 2014; M.R. Fernandes and L.S. Souza leg.; MNRJ 33983 . – Rio de Janeiro State • [4, 3 d] specs; Campos Basin; 22°42´S, 40°40´W; 12 m depth; 22 Mar. 2004; MNRJ 30854 • [22, 2 d] specs; Campos Basin ; 22°42´S, 40°40´W; 2006; MNRJ 18751 • [3] specs; Campos Basin ; 22°42´S, 40°40´W, 5–10 m depth; 2007; MNRJ 15402 • [65, 1 d] specs; same data as for preceding; MNRJ 29763 • [1] spec.; same data as for preceding; MNRJ 32962 • [4] specs; same data as for preceding; MNRJ 33136 • [2, 2 d] specs; Prainha, Arraial do Cabo ; 14 Mar. 2015; M.R. Fernandes and L.S. Souza leg.; MNRJ 26840 • [1] spec.; Praia do Forno, Arraial do Cabo ; 14 Mar. 2015; M.R. Fernandes and L.S. Souza leg.; MNRJ 26830 • [2, 2 d] specs; Enseada do Cardeiro, Arraial do Cabo ; 6 m depth; 12 Sep. 2015; M.R. Fernandes and L.S. Souza leg.; MNRJ 34616 • [1] spec.; Ilhas Maricás, Maricá ; 8 m depth; 12 Feb. 2015; M.R. Fernandes and L.S. Souza leg.; MNRJ 34242 .

Description of basic anatomy

EXTERNAL MORPHOLOGY. Body white, head and anterior/lateral portions of foot mainly black, cephalic tentacles and ventral part of the foot entirely white; pedal slit covering 65–80% of foot length.

OPERCULUM. Ovate, thin, semi-transparent, membranous, multispiral, ~4.25 whorls, nucleus subcentral, dislocated 22–26% from center toward margin.

JAW. Wing-shaped; outer side with scales rectangular/squared, rectangular-bilobed (resembling tiles), bone-shaped or occasionally acute-lanceolate; scales with micro-pores up to 400 nm in diameter; inner side with scales oblong-lanceolate or hexagonal/gem-like, surface smooth; scales of outer side 10.0– 13.2 µm long, 3.4–6.2 µm wide, ratio length/width 2.0–3.0 (rectangular scales), 10.0– 11.5 µm long, 2.7–6.0 µm wide, ratio length/width 1.9–3.8 (rectangular-bilobed), 11.5–12.7 µm long, 3.4–3.8 µm wide, ratio length/width 3.2–3.4 (bone-shaped); scales of inner side usually 12.4–15.3 µm long, 5.4–7.1 µm wide, ratio length/width 2.1–2.6 (oblong-lanceolate scales), 12.5–13.0 µm long, 7.0– 7.4 µm wide, ratio length/width 1.7–1.8 (hexagonal).

RADULA. Formula 14-1-1-1 -14; central and lateral teeth with three cusps similarly sized, with a parrotbeak appearance, outer cusps slightly oriented outwards and slightly broader and more prominent than median cusp; a very small process may appear on the side of cusp 1 of lateral teeth; marginal teeth with three cusps, median one much thinner and elongated (1.6–2.9× longer than outer cusps), resembling a malleable filament, outer cusps curved in inner teeth (somewhat similar to outer cusps of central and lateral teeth, but not oriented outwards as the latter) but more triangular and elongated in outer teeth; median cusp of marginal teeth develops in the lower half of tooth, outer cusps develop in the top of tooth; base of marginal teeth more developed than that of central and lateral teeth; central tooth 3.5–5.7 µm wide, lateral teeth 3.1–5.4 µm wide, inner marginal teeth 2.0– 3.9 µm wide, outer marginal teeth 1.6–3.4 µm wide.

Remarks

Despite being one of the commonest triphorids in the western Atlantic, S. intermedia has its external morphology, operculum, jaw and radula firstly illustrated in the present study. Just like its congeneric species from the eastern Atlantic, the anterior portion of the animal has a dark pigmentation even after stored in ethanol ( Fig. 25 A–B). The operculum of S. intermedia , with a subcentral nucleus ( Fig. 25 C–E), is similar to that of S. triclotae Bouchet, 1997 ( Bouchet 1997: fig. 9A). The tooth morphology of S. intermedia is also very similar to those of S. similior ( Bouchet & Guillemot, 1978) and S. triclotae , with all teeth bearing three cusps but the marginal teeth showing a median cusp much elongated, 1.6–2.9× longer than outer cusps in S. intermedia (two times longer in S. triclotae ; two to four times longer in S. similior ). The number of marginal teeth is also slight conservative in the genus, with 14 in S. intermedia , 15 in S. triclotae and 13–16 in S. similior .

Figures

Fig. 2. Specimens studied. A. Metaxia excelsa Faber & Moolenbeek, 1991 (MZSP 122353). B. Metaxia rugulosa (C.B. Adams, 1850) (BMSM 56034). C. Cosmotriphora melanura (C.B. Adams, 1850) (MNRJ 33980). D. Iniforis pseudothomae Rolán & Fernández-Garcés, 1993 (MZSP 100957). E. Latitriphora albida (A. Adams, 1854) (BMSM 55442). F. Monophorus olivaceus (Dall, 1889) (MNRJ 34615). G. Nanaphora verbernei (Moolenbeek & Faber, 1989) (MZSP 85022). H. Nototriphora decorata (C.B. Adams, 1850) (MNRJ 28941). I. Sagenotriphora osclausum (Rolán & Fernández-Garcés, 1995) (MNRJ 35061). J. Similiphora intermedia (C.B. Adams, 1850) (MNRJ 29763). K. Strobiligera gaesona (Dall, 1927) (MZSP 53685). L. “Inella” harryleei Rolán & Fernández-Garcés, 2008 (FLMNH 450495). Scale bars: 1 mm.

Fig. 25. Similiphora intermedia (C.B. Adams, 1850). A–C, F–H. MNRJ 30854. D. MNRJ 18751. E. MNRJ 29763. A–B. External morphology. C–E. Operculum. F–H. Head-foot (F) and ctenidium (G–H) critical-point dried. Scale bars: A–B = 500 µm; C–G = 100 µm; H = 50 µm.

Fig. 26. Similiphora intermedia (C.B. Adams, 1850). A–C, F. MNRJ 18751. D–E. MNRJ 30854. G. MNRJ 29763. A–G. Jaw, outer (A–C, G) and inner (D–F) sides. Scale bars: A = 20 µm; B, G = 5 µm; C = 1 µm; D = 50 µm; E–F = 10 µm.

Fig. 27. Similiphora intermedia (C.B. Adams, 1850), radula. A–D. MNRJ 30854. E–G. MNRJ 29763. Scale bars: A–B, D–E = 10 µm C, F = 5 µm; G = 2 µm.