Graptacme perlonga (Dall, 1881 )

Caetano, Carlos Henrique Soares, Scarabino, Victor & Absalão, Ricardo Silva, 2006, Scaphopoda (Mollusca) from the Brazilian continental shelf and upper slope (13 º to 21 ºS) with descriptions of two new species of the genus Cadulus Philippi, 1844, Zootaxa 1267, pp. 1-47 : 20-21

Graptacme perlonga (Dall, 1881)

Figs. 44–45

+ Dentalium perlongum Dall 1881: 36 ; 1889: 76, pl. 27, fig. 6.

+ Dentalium (Laevidentalium) perlongum: Pilsbry and Sharp 1897: 104 , pl. 18, figs. 10, 11; Henderson 1920: 75, pl. 9, fig. 1; Maury 1922: 38; Lange de Morretes 1949: 54; Turner 1955: 313; Rios 1970: 144.

+ Graptacme perlongum: Scarabino 1985: 199 , pl. 72, fig. 1018; 1994: 307, pl. 105, fig. 1506. + Graptacme perlonga: Steiner & Kabat 2001: 446 ; 2004: 629.

Type material

Lectotype MCZ 7752 (designated by Turner, 1955: 319 as " Holotype "); Paralectotypes MCZ 7660, 1 dd, MCZ 7661, 1 dd, MCZ 7663, 1 dd, MCZ 7664, 3 dd.

Diagnosis

Shell long (to 90 mm), slender, solid, almost straight. Surface smooth but apical portion shows longitudinal striae. Apex with a U­shaped notch on ventral side.

Material examined

Lectotype and Paralectotype MCZ 7660 of Graptacme perlonga ; IBUFRJ 13866, sta 517, 1 dd; IBUFRJ 14309, off Bacia de Campos, Rio de Janeiro, 1000–1600 m, 3 lv, 20 dd.

Distribution

USA: North Carolina to Florida; gulf of Mexico; Grenada (Henderson 1920); Brazil: Ceará (Henderson 1920), Bahia and Rio de Janeiro (this study). Living 1000–1600 m (this study), empty shells 200 to 4850 m (Steiner & Kabat 2004).

Remarks

Turner ( 1955: 319) recognized the specimen from MCZ 7752 as the only one that agrees with the original description and illustration of Graptacme perlonga , wrongly using the term holotype to designate this specimen since Dall ( 1881) did not designate a holotype. Steiner & Kabat ( 2004) considered Turner’s " holotype " as the lectotype. Turner’s use of the term " holotype " falls within the conditions of ICZN Art. 74.5 to accept a " holotype " indication as a lectotype designation, because Turner ( 1955) knewn that Dall ( 1881) did not select any specimen as holotype. Turner’s lectotype designation is valid.

Henderson ( 1920) cited specimens from Rio de Janeiro and off Rio de la Plata, Uruguay, the latter also indicated by Scarabino ( 1973). Penna­Neme ( 1974) recorded this species from the coast of Maranhão, at Ilha Grande­Rio de Janeiro and south of Brazil. Cabral and Mello ( 1994: 38, fig. 9) reported it for the states of Ceará and Alagoas. We do not consider those records to belong to G. perlonga , because all were based on specimens gathered in depths ranging from the shore to 170 m, while this species has a bathyalabyssal distribution being collected from depths greater than 200 m (Steiner & Kabat 2004). Additionally, we examined the material from Scarabino ( 1973) and Penna­Neme ( 1974) studies, which prooved to be misidentified specimens. Recently, Scarabino ( 2003) stated that G. perlonga records from off Argentina were obviously due to a mistake in the station number, as suspected previously by Henderson ( 1920), who added a question mark to this record. Thus, we conclude that the southernmost geographical distribution limit for this species is off Rio de Janeiro, Brazil.

Figures

FIGURES 39 – 56. Genus Graptacme and Fustiaria. (39 – 43) Graptacme calamus, (39 – 40) Lectotype USNM 68117, 19 mm, (41 – 43) IBUFRJ 14232, 18 mm; (44 – 45) Graptacme perlonga, IBUFRJ 13866, 61 mm; (46 – 47) Graptacme semistriolata, IBUFRJ 14247, 35 mm; (48 – 52) Fustiaria liodon, (48) Holotype ANSP 35554, 25 mm, (49 – 52) IBUFRJ 14252, 30 mm; (53 – 56) Fustiaria stenoschiza, (53 – 54) Syntype ANSP 71081, 35 mm, (55 – 56), IBUFRJ 10587, 26 mm.