Triphora charybdis Fernandes & Pimenta, 2015

Fernandes, Maurício Romulo & Pimenta, Alexandre Dias, 2020, Unraveling one of the ‘ Big Five’: update of the taxonomy of Triphoridae (Gastropoda, Triphoroidea) from Brazil, European Journal of Taxonomy 665 (665), pp. 1-170 : 51-53

Triphora charybdis Fernandes & Pimenta, 2015

Figs 21 I–N, 24S, 77, 83, 84E

Triphora charybdis Fernandes & Pimenta, 2015: 507 , fig. 7C–K.

Material examined

Holotype

BRAZIL – Rio de Janeiro • 23º10′01″ S, 41º03′13″ W; depth 107 m; MNRJ 18620 *.

Paratypes

See Fernandes & Pimenta (2015).

Other material

BRAZIL – Ceará • 1 spec.; 02º14′25″ S, 38º22′50″ W, Canopus Bank; depth 260 m; Nov. 2005; MZSP94263 . – Rio Grande do Norte • 2 specs; 04º44′11′ S, 36º24′55″ W; depth 425–450 m; 7 May 2011; MNRJ 35109 * • 1 spec.; 04º44′53″ S, 36º25′27″ W; depth 102–108 m; 23 May 2011; MNRJ 35116 * • 2 specs; 04º33′17″ S, 36º56′35″ W; depth 130–160 m; 21 May 2011; MNRJ 35180 *. – Alagoas • 1 worn spec.; 10º32′07″ S, 36º05′11″ W, MARSEAL st. BN4-R1; depth 400 m; UFS . – Rio de Janeiro • 3 specs; PADCT st. 6627; MNRJ 29387 *. – São Paulo • 1 spec.; REVIZEE-Sul st. 6666; MNRJ 29379 * • 3 specs; REVIZEE-Sul st. 6653; MNRJ 60189 . – Paraná • 1 spec.; REVIZEE-Sul st. 6699; MNRJ 29388 * • 3 specs; PADCT st. 6641; MZSP 133498 • 3 specs; PADCT st. 6595; MNRJ 29386 *. – Santa Catarina • 1 spec.; PADCT st. 6635; MNRJ 29380 *. – Rio Grande do Sul • 1 spec.; off Solidão ; 30º42′ S, 49º03′ W; depth 182–186 m; 6 Aug. 1972; OC. Ship W. Besnard leg.; MZSP 19331 .

COLOMBIA • 1 spec.; Archipiélagos Coralinos ; 09º51′46″ N, 76º09′02″ W; depth 101 m; 30 Apr. 2005; A. Clavijo leg.; INV MOL6534 • 2 specs; Archipiélagos Coralinos ; 09º48′04″ N, 76º11′09″ W; depth 95 m; 29 Apr. 2005; A. Clavijo leg.; INV MOL6538 • 1 spec.; Archipiélagos Coralinos ; 09º47′17″ N, 76º11′56″ W; depth 98 m; 1 May 2005; A. Clavijo leg.; INV MOL6531 • 1 spec.; Archipiélagos Coralinos ; 09º46′36″ N, 76º12′49″ W; depth 102 m; 29 Apr. 2005; A. Clavijo leg.; INV MOL6532 .

GUYANA • 1 spec.; 08º08′00″ N, 57º52′30″ W, R/V Chain Cruise 35, station 37; depth 82–110 m; 28 Apr. 1963; MCZ 273420 .

Remarks

Fernandes & Pimenta (2015) indicated that well-preserved shells of Triphora charybdis were sampled only in southeastern Brazil, and worn shells from Amapá and Santa Catarina were probably subfossil forms. Herein, the range of T. charybdis is extended based both on preserved and worn material ( Fig. 77 ). Shells with a faint coloration are present northward up to the Guyana ( Fig. 21I ) and southward to Rio Grande do Sul ( Fig. 84E ). Small adult shells were found in Colombia ( Fig. 21 K–N), and their intact conditions indicate that this species is currently present there.

Triphora charybdis may have remained unnoticed in the Caribbean because of its moderately deep habitat, i.e., the mid-low depths of the continental shelf, and similarities with other shallow-water triphorids ( Fernandes & Pimenta 2015). However, if the pattern of worn vs preserved shells in the range of T. charybdis is confirmed after the availability of more material, a scenario of range retraction in northern and southern Brazil will be likely. In this case, living T. charybdis would be restricted to tropical waters of northeastern and southeastern Brazil, with the population from Colombia being increasingly diverged because of the lack of gene flow; their small adult size may be indicative of such a divergence.

Geographical records

Colombia (this study – well preserved); Guyana (this study – worn); Brazil: Amapá to Ceará ( Fernandes & Pimenta 2015; this study – worn), Rio Grande do Norte to Rio de Janeiro ( Fernandes & Pimenta 2015; this study – well preserved), São Paulo to Rio Grande do Sul ( Fernandes & Pimenta 2015; this study – worn).

Bathymetric distribution

Depth: 80 m ( Fernandes & Pimenta 2015) to 186 m (this study). Some deeper records, down to 450 m, are anomalous and probably derived from post mortem dislodgement.

Invalidation of previous record in Brazil

Figures

Fig. 21. A–F. Cosmotriphora cf. melanura (C.B. Adams, 1850). A. MORG 14448*, 6.15 mm. B. MORG 39890*, 2.10 mm. C. MNRJ 32421*, 5.97 mm. D. MORG 24616*, 5.09 mm. E. MNRJ 35176*, 7.24 mm. F. MZSP 70279, 7.35 mm. — G–H. Iniforis carmelae Rolán & Fernández-Garcés, 1993. G. MNRJ 35184*, 4.40 mm. H. IBUFRJ 17351, 3.38 mm. — I–N. Triphora charybdis Fernandes & Pimenta, 2015. I. MCZ 273420, 7.75 mm. J. MNRJ 35109*, 6.57 mm. K–L. INV MOL6534, 4.25 mm. M–N. INV MOL6531, 3.39 mm. Scale bars: A–M = 1 mm; N = 500 µm. Photo credits K–N: Erika Montoya (INVEMAR).

Fig. 77. Distribution map of Triphora charybdis Fernandes & Pimenta, 2015; red circle = type locality.

Fig. 84. Fresh and worn specimens found in southern Brazil and Uruguay/Argentina. A. Nanaphora verbernei (Moolenbeek & Faber, 1989), MNRJ 28956*. B. Nototriphora decorata (C.B. Adams, 1850), MNRJ 28941*. C. Triphora ellyae De Jong & Coomans, 1988, MNRJ 23259. D. Similiphora intermedia (C.B. Adams, 1850), MNRJ 23366. E. Triphora charybdis Fernandes & Pimenta, 2015, MZSP 19331. F–J. Marshallora sp. F–I. MNHN-Mo 12959*, La Paloma, Rocha, Uruguay, E. Duarte leg., 6 Apr. 1959. J. MLP 26399, Cantera La Elvira, Buenos Aires Province, Argentina, M. Aguirre leg., 1983. Scale bars: 1 mm.; J not to scale.