Iniforis pseudothomae Rolán & Fernández-Garcés, 1993

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 : 18-21

Iniforis pseudothomae Rolán & Fernández-Garcés, 1993

Figs 2D , 9–11

Material examined

BRAZIL – Bahia State • [1, d] spec.; Garapuá, Morro de São Paulo, Cairu ; Dec. 2008; MNRJ 32881 • [1, d] spec.; Praia de Garapuá, Morro de São Paulo, Cairu ; 5 m depth; 2011; P. Coelho-Filho leg; MZSP 100957 .

Description of basic anatomy

OPERCULUM. Ovate, thin, semi-transparent, membranous, with a yellow border, poorly distinct whorls and nucleus; small triangular projection at the border, its length being 14% of diameter of operculum; diameter of operculum exceeds diameter of opercular pouch in ~20%.

JAW. Wing-shaped; outer side with scales acute-lanceolate, rectangular/squared, rectangular-bilobed or irregular; scales with micro-pores up to 350 nm in diameter, concentrated in the posterior region (close to the radula); inner side with scales moderately lanceolate, hexagonal or rhombus-shaped, surface smooth; scales of outer side 16.3–22.6 µm long, 5.2–8.7 µm wide, ratio length/width 2.4–3.4 (acute-lanceolate scales), 9.7–12.4 µm long, 3.9–6.1 µm wide, ratio length/width 1.7–3.1 (rectangular), 8.8–15.3 µm long (squared), 10.2–11.3 µm long, 4.3–4.9 µm wide, ratio length/width 2.2–2.5 (rectangular-bilobed); scales of inner side 13.0– 14.2 µm long, 4.3–5.4 µm wide, ratio length/width 2.5–3.2 (lanceolate), 14.7–19.4 µm long, 6.3–8.9 µm wide, ratio length/width 2.0–2.4 (hexagonal/rhombus-shaped).

RADULA. Up to 41 undifferentiated and overcrowded teeth per row; narrow teeth, usually hook-shaped, with three elongated or slightly curved/claw-like cusps, median cusp equal or up to 1.5× more elongated than outer ones; outer marginal teeth with three elongated cusps, median cusp usually increases towards last marginal teeth and is 1.3–1.6× more elongated than outer cusps; undifferentiated teeth 1.4–1.8 µm wide, outer (last) marginal teeth 1.3–1.6 µm wide.

Remarks

Despite the loss of pigmentation in specimens herein studied due to their long storage in ethanol, I. pseudothomae still shows distinct yellow border in the operculum ( Fig. 9B ). Rolán & Fernández- Garcés (1993) also observed a yellow pigmentation in the propodium and metapodium of I. turristhomae (Holten, 1802) . They cited, but did not illustrate, the presence of an ‘ovoid insertion surface form’ in a lateral position of the operculum, which may resemble the small triangular projection present in the border of the operculum of I. pseudothomae ( Fig. 9E ).

The tooth morphology of I. pseudothomae seems identical to that of I. turristhomae ( Bandel 1984; Rolán & Fernández-Garcés 1993), with many undifferentiated teeth that usually bear three hooked cusps ( Fig. 11 ). A complete radular row of I. pseudothomae contains 41 teeth, instead of 28 in I. turristhomae ( Bandel 1984) . Similar teeth with three hooked cusps are also present in I. malvacea Jousseaume, 1884 and I. violacea (Quoy & Gaimard, 1834) ( Marshall 1983) . The Japanese species Mastoniaeforis albogranosa (Kosuge, 1961) was traditionally allocated to Iniforis , leading to Rolán & Fernández-Garcés (1993) erroneously interpret that this genus has a variable number of cusps per teeth based on Kosuge (1966); Marshall (1983: 45) already indicated the allocation of the latter species in Mastoniaeforis Jousseaume, 1884 , although not explicitly as a new combination.

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. 9. Iniforis pseudothomae Rolán & Fernández-Garcés, 1993. A–B, E. MNRJ 32881. C–D. MZSP 100957. A–B. External morphology. C–D. Ctenidium. E. Operculum. Scale bars: A–B = 1 mm; C = 200 µm; D = 50 µm; E = 100 µm.

Fig. 10. Iniforis pseudothomae Rolán & Fernández-Garcés, 1993. A–E. Jaw, inner (A) and outer (B–E) sides. A–B, E. MZSP 100957. C–D. MNRJ 32881. Scale bars: A–B = 20 µm; C–D = 10 µm; E = 2 µm.

Fig. 11. Iniforis pseudothomae Rolán & Fernández-Garcés, 1993, radula. A–F. MZSP 100957. G–H. MNRJ 32881. Scale bars: A = 10 µm; B–D, F, H = 5 µm; E, G = 2 µm.