Fargoa bushiana (Bartsch, 1909)

Pimenta, Alexandre Dias, Absalão, Ricardo Silva & Miyaji, Cintia, 2009, A taxonomic review of the genera Boonea, Chrysallida, Parthenina, Ivara, Fargoa, Mumiola, Odostomella and Trabecula (Gastropoda, Pyramidellidae, Odostomiinae) from Brazil, Zootaxa 2049, pp. 39-66 : 55-57

Fargoa bushiana (Bartsch, 1909)

( Figs 44−47 )

Odostomia (Chrysallida) bushiana Bartsch 1909: 99 , pl. 13, fig. 44. Abbott 1974: 293, not illustrated.

Miralda dux auct. non Dall & Bartsch, 1906: Odé and Speers 1972: 9, fig. 4.

Odostomia (Chrysallida) dux : auct non Dall & Bartsch, 1906: Rios 1975: 143, pl. 43, fig. 660; 1985, pl. 54, fig. 775. Mello 1990: 41, fig. 15.

Fargoa bushiana: Robertson 1978: 375 , fig. 7. Robertson and Mau-Lastovicka 1979: 325, not illustrated, listed in a comparative table of hosts. Rios 1994: 187, pl. 61, fig. 872, figure reproduced from Bartsch (1909).

Odostomia (Chrysallida) bushiana: Rios 1985: 163 , pl. 54, fig. 774, figure reproduced from Bartsch (1909).

Chrysallida buijsei Jong & Coomans, 1988: 123 , pl. 19, figs 646a, b. New synonym.

Fargoa dux auct non Dall & Bartsch, 1906: Lyons 1989: 29, pl. 12, fig. 9.

Ividia dux auct non Dall & Bartsch, 1906:? Odé 1993b: 59, not illustrated.

Ividia bushiana :? Odé 1993b: 60, not illustrated.

Types and type locality: Holotype USNM 159101; Narragansett Bay, New England (10 m) ( Fig. 44 ).

Material examined: the holotype of Fargoa buijsei ( ZMA 3.87.102) and: --Maranhão State: MNHN, São Luiz (areia preta) [7]; --Pernambuco State: MNHN, Recife (praia do Pina) [5]; MNHN, Cabo (Praia de Gaibu) [23]; MNHN, Paulista (Maria Farinha) [7]; MNHN, Itamaracá (praia de Jaguaribe) [2]; MNHN, Cabo (enseada dos corais) [3]; MNHN, Cabo (pedras pretas) [2]; MNRJ 10958, Cabo (Praia de Gaibu) [4]; --Bahia State: MNHN, Plage de Rio Vermelho [1]; --Espírito Santo State: IBUFRJ 8503, off Piúma, 1993 [11]; --Rio de Janeiro State: IBUFRJ 9625, Arquipélago de Santana, Macaé, v/1993, AG coll. [67]; IBUFRJ 12327, REVIZEE Central Sta VV22 (20°25’S, 40°05’W, 33 m), 27/ii/1996, NOAN coll. [3]; IBUFRJ 13042, REVIZEE Central Sta VV24 (20°S, 39°54’W, 45 m), 27/ii/1996, NOAN coll. [11]; IBUFRJ 7511, off Rio de Janeiro State, 27/viii/1979, NOAC coll. [7]; IBUFRJ 7512, off Rio de Janeiro State, 27/viii/1979, NOAC coll. [4]; IBUFRJ 13666 Praia da Figueira, Angra dos Reis, 1998, C. Alvarenga coll. [30]; --other localities in southeast and south of Brazil -- PADCT expedition: MZSP 86838, sta 6541 [5]; MZSP 86839, sta 6635 [4]; MZSP 86840, sta 6611 [3]; MZSP 86841, sta 6577 [6]; MZSP 86842, sta 6571 [29]; MZSP 86843, sta 6595 [32]; MZSP 86844, sta 6606 [17]; MZSP 86845, sta 6579 [3]; REVIZEE expedition: MNRJ 10963, sta 6652 [9]; MZSP 86846, sta 6657 [8]; MNRJ 10962, sta 6662 [5]; MZSP 86847, sta 6669 [5]; MZSP 86848, sta 6658 [11]; MZSP 86849, sta 6653 [2].

Remarks: As discussed under Boonea, Robertson (1978, 1996) considered Fargoa a distinct genus, based on anatomical and reproductive characters, external morphology and host preferences (of Fargoa bartschi ). Robertson (1996) included in Fargoa both highly sculptured shells and nearly smooth ones. He assumed that the similarities of the protoconch, external anatomy and reproductive characters of F. bartschi and Fargoa diantophila ( Wells & Wells, 1961) were indicative of their congeneric status, and postulated that both species have undergone evolutionary divergence in shell sculpturing.

Fargoa bushiana (Bartsch, 1909) is very similar to Fargoa dux ( Dall & Bartsch, 1906) from Japan. Both have the same pattern of spiral sculpture including three nodulose cords, the first two attached by their nodules, and a smooth posterior cord. Odé and Speers (1972) noticed this similarity and suggested the possibility of a synonymy between them, but decided to use the name Miralda dux for the specimens from Texas. In 1993b, Odé went further, considering Chrysallida buijsei Jong & Coomans, 1988 a junior synonym of Fargoa dux , but allocated to the genus Ividia , and considered that a worldwide distribution for this species is probable.

Robertson (1978), on the other hand, argued against a worldwide distribution, suggesting that there could be convergences between eastern American species and the Far East ones, and preferred to use the western Atlantic name already established. Also, Robertson (1978) examined specimens from Brazil and considered them as conspecific with F. bushiana . The holotype ( Fig. 44 ) and Brazilian specimens ( Figs. 46−47 ) show some variation, especially in the degree of coalescence of the two anterior nodulose spiral cords. The holotype of C. buijsei ( Fig. 45 ) has the same shell shape, protoconch and sculpture pattern as F. bushiana , and is herein confirmed as a synonym of F. bushiana .

A shell from the Holocene of Argentina, illustrated in Farinati (1993: 308, fig. 18), with the name Odostomia (Menestho) impressa , is very similar and probably also corresponds to F. bushiana . This species has a large geographic range, from the Atlantic coast of the U.S.A. ( Abbott 1974) to southern Brazil (≅28o).

Figures

FIGURES 44 − 47. Fargoa bushiana: 44. holotype (USNM 159101); 45. holotype of Fargoa buijsei (ZMA 3.87.102); 46 − 47. (MNRJ 10958): 44 − 46. whole shell (lengths: 44: 2.2 mm; 45: 2.3 mm; 46: 2.0 mm); 47. last whorl. Scale bars: 250 Μm.