Taringa telopia

Alvim, Juliana & Pimenta, Alexandre Dias, 2013, Taxonomic review of the family Discodorididae (Mollusca: Gastropoda: Nudibranchia) from Brazil, with descriptions of two new species, Zootaxa 3745 (2), pp. 152-198 : 188-192

publication ID	https://doi.org/ 10.11646/zootaxa.3745.2.2
publication LSID	lsid:zoobank.org:pub:D87FBB64-5DE2-4D19-9338-6E9BE212FAEF
DOI	https://doi.org/10.5281/zenodo.6146318
persistent identifier	https://treatment.plazi.org/id/0387C073-FF85-6338-FF22-0EF5B05F5FC9
treatment provided by	Plazi
scientific name	Taringa telopia
status

Treatment

Taringa telopia View in CoL Er. Marcus, 1955

( Figures 2 View FIGURE 2. A – B D–F; 23–24)

Thordisa dubia Bergh, 1894: 178 , plt. 6, figs. 6–9.

Taringa telopia Er. Marcus, 1955: 152, figs. 166–179; García et al. (2008: 150); Rios (2009: 428, partly); Padula et al. (2012: 3).

Taringa telopia telopia Ev. Marcus, 1976a: 140; Ev. Marcus & Er. Marcus, 1967a: 87.

Taringa sp.: García et al. (2008: 152).

Taringa sp.1: Padula et al. (2012: 3).

Taringa sp.2: Padula et al. (2012: 3).

Type material. Probably lost; it is not located at the American Museum of Natural History (see Boyko & Sage, 1996; Valdés & Gosliner, 2001) or Museu de Zoologia / USP (MZSP) (present study). Holotype of Thordisa dubia : ZMUC GAS–2103, Rio de Janeiro state, Brazil.

Type locality. Ilha de São Sebastião, São Paulo state, Brazil.

Material examined. Brazil: Pernambuco state: Canal de Itamaracá: MNRJ 13186, 18 /i/2009, coll. F. Santos [2]; Alagoas state: Saco da Pedra: MNRJ 12922, 11 /i/2008, coll. J. Bahia [1; one dissected]; Recife do Porto: MNRJ 12923, 07 /i/2008, coll. J. Bahia [1]; Praia do Francês: MNRJ 13191, 09 /i/2008, coll. J. Bahia [2; one dissected]; Rio de Janeiro state: Búzios: Praia dos Ossos: MZSP 92400, 18 /ix/2009, coll. F. Santos [1]; Praia da Tartaruga: MNRJ 14970, 25 /v/2009, coll. J. Alvim [2; one dissected]; MNRJ 13782, 25 /ix/2009, colls. J. Alvim and Welligton [3; two dissected]; Cabo Frio: MNRJ 13182, 27 /viii/2005, coll. V. Padula [1]; Canal de Itajurú: MNRJ 11757, 15 /vii/2007, coll. J. Alvim [1]; MNRJ 14448, 23 /viii/2009, coll. J. Alvim [3; two dissected]; MNRJ 13993, 05 /vii/2009, coll. J. Alvim [1]; MNRJ 14924, 29 /ix/2009, coll. D. Couto [2; two dissected]; MNRJ 15035, 12 /xi/2009, coll. D. Couto [2; two dissected]; MNRJ 15033, 12 /xi/2009, coll. J. Alvim [1]; Praia das Conchas: MNRJ 13185, 25 /v/2005, coll. V. Padula [3; one dissected]; MNRJ 13183, 18 /ix/2005, coll. V. Padula [2]; MNRJ 13181, 25 /vi/2005, coll. F. Santos [2]; MNRJ 13184, 23 /iv/2005, coll. V. Padula [1; one dissected]; MNRJ 13192, ii/2007, coll. V. Padula [1]; MNRJ 13179, 23 –24/vii/2005, colls. F. Santos and V. Scarabino [7; two dissected]; Arraial do Cabo: Praia do Forno: MNRJ 14924, 24 /xi/2009, coll. J. Alvim [2]; MNRJ 12056, 20 /x/2007, coll. J. Alvim [2]; MNRJ 12741, 23 /vi/2007, coll. J. Alvim [1]; MNRJ 10787, 17 /vi/2006, coll. J. Alvim [1]; MNRJ 10795, 28 /v/2006, coll. J. Alvim [1]; MZSP 92248, 18 /ix/2009, coll. F. Santos [1]; Niterói: Gragoatão: MNRJ HSL7870, 22 /vi/1948, coll. Devoto [1]; Angra dos Reis: Praia de Mambucaba: MNRJ 15036, 15 /xi/2009, coll. J. Alvim [1]; São Paulo: Ilhabela: Praia do Portinho: MZSP 92740, 22 /xi/2002, colls. F. Santos, V.S. Amaral and P. Lima [1].

Geographical distribution. Colombia (Ev. Marcus, 1976a); Brazil: Pernambuco state: Canal de Itamaracá (present study); Alagoas state: Saco de Pedra, Praia do Francês, Pajuçara (Padula et al., 2012), Recife do Porto (present study); Rio de Janeiro state (Bergh, 1894): Búzios (García et al., 2008), Cabo Frio (Ev. Marcus & Er. Marcus, 1967a; Valdés & Gosliner, 2001), Arraial do Cabo, Niterói and Angra dos Reis (present study); São Paulo state: Ilha de São Sebastião (Er. Marcus, 1955).

Description. External morphology ( Figures 2 View FIGURE 2. A – B D–F; 23G): body elliptical, up 21.0 mm long alive, with two times greater length than width. Mantle densely covered by equidistant caryophyllidia, of approximately equal size (height: 100 µm); caryophyllidia lower in mantle edge and in center of mantle than those in sides of mantle, with variable number of spicules that protrude around tubercle. Tubercle apex with ciliary tuft, elongated and oval. Rhinophoral and branchial sheaths low and irregular covered by caryophyllia of same size as in centre of mantle. Rhinophores long with 10 to 12 diagonal perfoliations; cylindrical apex. Gill with six retractile, tripinnate branchial leaves, positioned symmetrically at longitudinal axis of body; anal cone high, located between two most posterior branchial leaves. Foot narrower than mantle, anteriorly bilabiated and notched on two lips; posteriorly foot may project beyond notum in a small rounded tail. Oral tentacles conical. Living specimens ranging in coloration from light orange to dark brown with blotches and spots brown all over dorsum with different sizes, and beige granules; these granules more often concentrated at edge and in center of mantle, and on rhinophoral and branchial sheaths; rhinophoral perfoliations brown with white blotches, rhinophore apex white; gill beige; foot ranging from whitish to light orange, may have tiny spots laterally.

Labial cuticle and radula ( Figures 23 View FIGURE 23 A–F): Labial cuticle smooth. Radula formula 31 x 3 –4.38–39.0.38– 39.4– 3 in specimen measuring 12.0 mm in length; lateral plates hook-shaped; innermost lateral teeth presents one or two denticles on outer side and inner side with wide variation from smooth up to five incipient denticles, varying in size and position on cusp; subsequent lateral teeth only with external denticles increasing in number outwards (up to 8 or 9); 3–4 marginal teeth spatulate and pectinate.

Reproductive system ( Figures 23 View FIGURE 23 H; 24A): hermaphrodite duct connecting to long and slightly convoluted ampulla. Postampullary gonoduct short, connecting to oviduct and prostate. Prostate granular and rounded, divided into two parts; proximal part smaller, whitish, less dense, and distal part larger, yellowish, denser. Vas deferens short, narrow and non-convoluted, opening into common atrium with vagina; vas deferens, near gonopore, presenting a cylindrical and smooth cuticle. Vagina elongated and narrow, opening into rounded and large bursa copulatrix. Bursa serially arranged, convoluted vaginal duct connecting to seminal receptacle; uterine duct short. Seminal receptacle with ¼ to 1/3 of diameter of bursa copulatrix.

Biology ( Figures 24 View FIGURE 24 B–C): egg mass forming a spiral ribbon with crenulated border. Ribbon presents 2–3 turns in the counterclockwise direction, and contains numerous rows of many tiny eggs (diameter: 86 µm to 91µm). Egg mass usually white, 9.0 mm to 11.0 mm in diameter. Only in two cases we found a rosy egg mass, and these egg masses were always near to other, white egg masses.

Remarks. Valdés and Gosliner (2001) demonstrated the synonymy between Taringa and Aporodoris and justified the use of the more recent name ( Taringa ), under ICZN (1999) conventions. Valdés and Gosliner (2001) also used Taringa telopia (the younger name) instead of Thordisa dubia , with the following justification: “ T. telopia has often been used in recent literature, whereas T. dubia was used as valid in the original description, more than a century ago”. However, this decision was not taken in accordance to ICZN (1999, article 23.9.2), since they did not explicitly cite the code or the 25 works where the younger name was used as valid, or use the terms nomen protectum and nomem oblitum. Thus, this situation is an erroneous reversal of precedence (ICZN, 1999: article 23.10) and should be referred to the Commission and, according to the code, the junior name is to be maintained (ICZN, 1999: article 23.9.3 [Art. 82]).

Er. Marcus (1955) described the genus Taringa to include T. telopia from São Paulo state, Brazil, but considered this species to be very similar to Thordisa dubia Bergh, 1894 from the coast of Rio de Janeiro state, which was described based on a single specimen. The only difference was the cuticle in the penis, a characteristic not mentioned by Bergh (1894) for Thordisa dubia . Therefore, Valdés and Gosliner (2001) analyzed Bergh’s illustrations (1894: Figs. 6–9 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 ) and considered these names as synonyms due to radular similarity, yet they did not mention the lack of the cuticle in the penis pointed out by Er. Marcus (1955).

Ev. Marcus and Er. Marcus (1967a) recognized two subspecies: Taringa telopia telopia and Taringa telopia disa Ev. Marcus & Er. Marcus, 1967a — the latter from Florida — based on differences in the radula: number of rows (about 32 in T. telopia telopia and 42 in T. telopia disa ), number of teeth per row (up to 45 in T. telopia telopia and at least 53 in T. telopia disa ), and number of denticles on the inner side of the innermost lateral tooth.

The recognition of two subspecies is still controversial, with the available data being differently interpreted. For example, Ortea et al. (1982) considered there to be more than one species in T. telopia , whereas Valdés et al. (2006) considered the two names as synonyms, but did not provide discussion to justify their decision. In fact, the number of rows and the number of teeth per row are characters with a wide range of radular variation in opisthobranchs, and should not be used to distinguish taxa, unless a ratio between the number of rows and the number of teeth per half-row was determined (Bertsch, 1976). The number of denticles on the inner surface of the innermost lateral tooth varies in the same radula in both T. telopia telopia ( Figs. 23 View FIGURE 23 C–E) and in T. telopia disa , which leads us to believe that we cannot use this character to separate subspecies. Nonetheless, we analyzed a large number of specimens of T. telopia from Brazil that were not mentioned by Ev. Marcus and Er. Marcus (1967a), which permits the recognition of T. telopia and T. disa as two valid species.

A diagnostic feature is related to the outer surface of the innermost lateral tooth: specimens of T. telopia present one or two denticles on the cusp; this occurs in the fifteen radulae dissected in the present work ( Figs. 23 View FIGURE 23 A– B), whereas in T. disa , we could identify four denticles (Ev. Marcus & Er. Marcus, 1967a). In addition, there are always four or five marginal teeth in T. telopia ( Fig. 23 View FIGURE 23 F), and in contrast to T. disa , six marginal teeth were never observed (Ev. Marcus & Er. Marcus, 1967a).

Taringa telopia is a species with high variation in external coloration: living specimens range from light orange to dark brown, almost black in some cases (Padula et al., 2012:7, Fig. 7 View FIGURE 7 b), and the pattern of brown blotches and spots and beige granules is highly variable ( Figs. 2 View FIGURE 2. A – B D–E), sometimes presenting without blotches, spots and granules ( Fig. 2 View FIGURE 2. A – B F). Despite this large variation in color, there were no significant differences that would allow the subdivision of this species.

García et al. (2008) designated a specimen as Taringa sp., which presents small and smooth innermost lateral teeth. In line with this, absence of denticle(s) on the outside of the innermost lateral tooth was observed in only one of the specimens studied here. This lack of denticle(s) is apparently related to the diminutive size of the specimen, which was a juvenile (4.0 mm in length), so we believe that this is an ontogenetic variation present within T. telopia .

Padula et al. (2012) distinguished two morphotypes from the Brazilian coast (Alagoas state): Taringa sp. 1 and Taringa sp. 2. The first is much darker than the usual morphotype of Taringa telopia , and all specimens dissected in the present study display a single denticle on the outer surface of the innermost lateral teeth and show other minor differences in the reproductive system. Despite these small differences, we consider this as intraspecific variation, at least for now. Future studies using additional specimens of morphotype “ Taringa sp. 1” need to be performed. Taringa sp. 2 is apparently a juvenile.