Nototriphora decorata (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 : 33-37

Nototriphora decorata (C.B. Adams, 1850)

Figs 2H , 21–23

Material examined

BRAZIL – Rio de Janeiro State • [1] spec.; Campos Basin ; 22°42´S, 40°40´W; MNRJ 33137 • [5, 3 d] specs; Ilha do Aleijado , Angra dos Reis; MNRJ 32763 • [2, 1 d] specs; Ilha Cunhambebe Grande, Angra dos Reis ; 22°58´04″ S, 44°24´52″ W; intertidal; 29 Sep. 2008; A. Breves leg.; MNRJ 19785 • [4, 1 d] specs; Ilha da Gipóia , Angra dos Reis; 2003; MNRJ 28854 . – São Paulo State • [9, most juvs, 2 d] specs; Ilhabela ; 29 Mar. 2007; P. Longo leg.; in Sargassum sp.; ZUEC-GAS 1803-1811 . – Santa Catarina State • [7, 2 d] specs; Praia da Sepultura, Bombinhas ; 27°08´31″ S, 48°28´40″ W; 20 Dec. 2016; M.R. Fernandes leg.; MNRJ 28941 • [1] spec.; Praia da Tainha, Bombinhas ; 27°12´59″ S, 48°30´40″ W; 21 Dec. 2016; M.R. Fernandes leg.; MNRJ 28957 .

Description of basic anatomy

OPERCULUM. Rounded to slightly elliptical, thick, slightly opaque, yellowish, corneous, multispiral, up to 4.75 distinct whorls, nucleus subcentral, dislocated 21–27% from center toward margin; diameter of operculum exceeds diameter of opercular pouch in ~20%.

JAW. Wing-shaped; outer side with scales boomerang-shaped, rectangular, rhombus-shaped, puzzleshaped or X-shaped; scales of outer side 9.1–9.9 µm long, 3.0–4.0 µm wide, ratio length/width 2.5–3.2 (boomerang-shaped), 10.2–10.9 µm long, 4.3–4.9 µm wide, ratio length/width 2.1–2.5 (rectangular), 14.1–15.7 µm long, 5.5–6.4 µm wide, ratio length/width 2.4–2.6 (rhombus-shaped), 11.3–12.8 µm long, 1.9–2.2 µm wide, ratio length/width 5.6–6.4; scales with micro-pores up to 500 nm in diameter; inner side with smooth lanceolate scales, 12.4–15.9 µm long, 3.9–5.8 µm wide, ratio length/width 2.7–3.8.

RADULA. Formula 18-1-1-1 -18; central tooth claw-like, with three nearly similar cusps, median cusp thinner, outer cusps more prominent and broader in the middle of its length, assuming a somewhat rhombus-shape; lateral teeth comb-like, with five similar cusps, but outer ones (cusps 1 and 5) slightly broader and more prominent, cusp 2 often slightly more reduced; M1 with four cusps, inner ones (cusps 2 and 3) much thinner and elongated (1.5–2.7× longer than cusps 1 and 4), resembling malleable filaments, cusps 1 and 4 curved, somewhat similar to outer cusps of central and lateral teeth; remaining marginal teeth similar to M1, but with three cusps, median one much elongated (1.5–2.5× longer than outer cusps); central tooth 3.1–4.1 µm wide, lateral teeth 3.4–4.7 µm wide, marginal teeth between 1.8 µm (outer teeth) to 3.7 µm wide (M1).

Remarks

García & Luque (1986) cited the existence of red spots on the flanks, near the operculum, of Caribbean specimens of N. decorata , which was not observed in specimens from Cuba studied by Rolán & Fernández-Garcés (1994) nor herein. Specimens analyzed by García & Luque (1986) could actually be wrongly identified as N. decorata , because a red pigmentation can be seen in other genera, such as Monophorus and Nanaphora .

Although briefly described by Rolán & Fernández-Garcés (1994), the thick and yellowish operculum of N. decorata is herein illustrated for the first time ( Fig. 21 C–E), superficially resembling those previously described for the genus, despite the operculum of N. decorata having fewer whorls and not being so tall as in the type species N. aupouria ( Marshall 1983) .

The radula herein described is identical to the Caribbean one described by Rolán & Fernández-Garcés (1994).Another similar radula is that of the eastern Atlantic species Nototriphora canarica (Nordsieck & Talavera, 1979) , with 17 marginal teeth ( Bouchet 1997). Both species also share a remarkably similar shell, being considered in the past as a single species (for detailed comparisons, see Bouchet 1985), and they have probably diverged recently.

Bouchet (1997) compared the radula of N. canarica with that of type species N. aupouria ( Marshall 1983) , finding discrete differences such as the latter species with four cusps in lateral teeth (instead of five), four cusps in M2 and M3 (instead of three), and a reduced number of marginal teeth (only nine). Such differences also apply to N. decorata , which has a similar radula to N. canarica . Even with the evident closer relationship of the two Atlantic species, their radula cannot be seen as diverging in a generic level to the type species owing to a very similar tooth morphology, except by the species-level differences listed above.

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. 21. Nototriphora decorata (C.B. Adams, 1850). A–B. MNRJ 28941. C. MNRJ 19785. D–E. MNRJ 32763. F, I–K. MNRJ 28854. G–H. ZUEC-GAS 1804. A–B. External morphology. C–E. Operculum. F–K. Jaw, inner (F) and outer (G–K) sides. Scale bars: A–B = 1 mm; C–E = 100 µm; F = 20 µm; G = 50 µm; H = 5 µm; I, K = 10 µm; J = 2 µm.

Fig. 22. Nototriphora decorata (C.B. Adams, 1850), radula. A–F. MNRJ 28854. Scale bars: A = 20 µm; B, D–F = 5 µm; C, 10 µm.

Fig. 23. Nototriphora decorata (C.B. Adams, 1850), radula. A. MNRJ 28854. B–C. ZUEC-GAS 1804. D–F. MNRJ 32763. Scale bars: A–C, E–F = 5 µm; D = 10 µm.