Paxyodon syrmataphorus – INHS Mollusk Collection

(Meuschen, 1781)

Original Description: Mya syrmataphora Meuschen in Gronovius, L.T. 1781. p. 260. species no. 1093. pl XVIII, figs. 1 and 2 in Zoophylacium Gronovianum, exhibens, Animalia, Quadrupeda, Amphibia, Pisces, Insecta, Vermes, Mollusca, Testacea, et Zoophyta.

Type Locality: “Habitat in fluminibus Guineae.”

Holotype: Location unknown.

Synonymy:

Triquetra subviridis Klein 1753
Klein 1753:135, pl. 9, fig. 36. Type locality: Guiana and Brazil?

Mya syrmataphora Meuschen, 1781

Meuschen in Gronovius, 1781:260, pl. 18, figs. 1, 2; Wood, 1825:12, pl. 2, fig. 36b.

Paxyodon ponderosus Schumacher, 1817

Schumacher 1817:46, pl. 11, fig. 3. Type locality: ???

Hyria syrmatophora (Meuschen, 1781)

Sowerby 1823, fig. d; 1839, fig. 143; Reeve, 1841:120, pl. 90, fig. 1; Wood, 1856:17, pl. 2, fig. 36; Hupe, 1857:79, pl. 15, fig. 2; Sowerby, 1869, pl. 5, fig. 2.

Tellina alata Linneaeus, 1???

Linneaeus 1???: Type locality: ???; Gray 1847:197.

Hyria avicularis Lamarck, 1819

Lamarck 1819:82??; Type locality: Brazil?; Children 1823:??; Olsson & Wurtz 1951:239.

Hyria avicularis var. b. Lamarck, 1819

Lamarck, 1819:82.

Margarita (Unio) syrmatophorus (Meuschen, 1781)

Lea, 1836:2; 1838:13.

Margaron (Triquetra) subviridis (Klein, 1753)

Lea, 1852:17; 1870:25.

Unio syrmatophora (Meuschen, 1781)

Deshayes, 1853:219, pl. 29, figs. 10-11.

Unio syrmatophorus (Meuschen, 1781)

von Martens 1873:210; Ernst, 1876:230.

Prisodon syrmataphorus (Meuschen, 1781)

Simpson 1900:870; 1914:1218; Baker 1930:63.

Prisodon syrmataphorus syrmataphorus (Meuschen, 1781)

Haas 1931:43.

Prisodon syrmataphorus complanatus (Hupé, 1857)

Haas 1931:43.

Paxyodon syrmatophorus (Meuschen, 1781)

Haas 1966:541.

Description: “Shell subtriangular or subtrapeziod, more or less inflated, solid, somewhat inequilateral; beaks full, more or less elevated, apparently without sculpture; posterior ridge high, generally narrowly rounded, often cord-like, occasionally semi-double below, ending at the shells base in a point or a narrow biangulation; dorsal line usually straight, ending in a wing before and behind; anterior end narrowed, cut away and rounded below; base straight or curved; posterior end obliquely or almost squarely truncate, its outline often incurved; surface having delicate striae of growth and fine, radiating lines and sometimes a few folds below the ligament; epidermis shining, greenish, greenish-yellow or brownish, often with metallic tints; teeth elongated, rather solid but compressed; pseudocardinals two or more in each valve; one lateral in the right valve and two in the left, all of them sometimes slightly vertically striate; muscle scars not deep; nacre bluish, flesh-colored or purplish.

Length 102, height 70, diam. 35 mm. Length 85, height 52, diam. 34 mm.” (Simpson, 1914:1218).

Range: Guiana; Brazil (Simpson, 1900:870).

Comments: Paxyodon syrmatophorus holds the distinct honor of being the first naiad ever described from South America. Klein (1753) first figured and described the Triquetra subviridis from Guiana and Brazil in 1753. Because Klein was a nonbinomial author, his name had to be rejected in favor of Mya syrmatophora Meuschen (1781) (type locality, Guiana). Because of the age of the name and subsequent misinterpretations of the identity of this species, it has undergone a number of name changes in the past 240 years.

Specimens Examined: ANSP 125546. (1 specimen, labeled as Triquetra subviridis). Orinoco. USNM 339717 (1). British Guiana. UCM 36453 (1). Lake Fundacion, 20 km E Soledad, on the floodplain of the Orinoco River, Anzoategui, Venezuela. 9 October 1988. UCM 36454 (1). Lake Tineo, 15 km E Soledad, on the floodplain of the Orinoco River, Anzoategui, Venezuela. 10 November 1988. UCM 36758 (1). Lake Tineo, 15 km E Soledad, on the floodplain of the Orinoco River, Anzoategui, Venezuela. 24 September 1988. M. Lasi. INHS 16980 (1). Río Orinoco, Palmarito, 15 km NE del centro Roblado Marhuanta, cerca de Isla Grande, Bolívar, Venezuela. 4 May 1994. Yomaera Molina de R. One specimen at UCV.

Literature Cited

Adams H, Adams A. 1858. The genera of recent Mollusca, arranged according to their organization. 3 vols. https://doi.org/10.5962/bhl.title.4772.

Baker HB. 1930. The Mollusca collected by the University of Michigan-Williamson Expedition in Venezuela. VI. Occasional Papers of the Museum of Zoology, University of Michigan. No. 210. 1-81 + 7 plates.

Bruguiere JG. 1792. Choix de memoires sur divers objets ‘histoire naturelle formant las collections du Journal d’Histoire Naturelle, I, p. 131.

D’Orbigny A. 1835. Synopsis terrestrium et fluviatilium molluscorum, In suo per Americam meridionalem itinere, ab. A. d’Orbigny, collectorum. Magasin de Zoologie. 6(61/62):1-44.

Dunker W. 1858. Einige neue species der Naiaden. Mal Blatt. ?:225-229.

Ernst A. 1876. Enumeracion sistematica de las especies de moluscos terrestres y de aqua dulce, halladas hasta ahora en los alrededores de Caracas y demas partes de la republica. pp. 225-230 in Estudois sobre la flora and fauna de Venezuela.

Gray JE. 1847. A list of the genera of recent Mollusca, etc. Proceedings of the Zoological Society of London XV:129-214.

Haas F. 1931. Versuch einer kritischen sichtung der Südamerikanischen Najaden. Senckenbergiana 30(2):87.

Haas F. 1966. Superfamilia Unionacea. Das Tierreich (Berlin). 88:x + 663 pp. https://doi.org/10.1515/9783111721569.

Johnson RI. 1979. The types of Unionacea (Mollusca: Bivalvia) in the Museum of Zoology, the University of Michigan. Malacological Review 12(1-2):29-36.

Lamarck JB. 1819. Histoire Naturelle des Animaux sans Vertebres. ?? pp. https://doi.org/10.5962/bhl.title.12712.

Lea I. 1870. Synopsis of the Family Unionidae. 4th Edition, very greatly enlarged and improved. Henry C. Lea, Philadelphia. 184 pp. https://doi.org/10.5962/bhl.title.46363.

Lea I. 1871. Description of three new species of exotic Unionidae. Proceedings of the Academy of Natural Sciences of Philadelphia 1871:188.

Lea I. 1874a. Journal of the Academy of Natural Sciences of Philadelphia Vol. VIII. ?? pp.

Lea I. 1874b. Observations on the genus Unio. XIII. ?? pp. https://doi.org/10.5962/bhl.title.11214.

Marshall WB. 1922. New pearly fresh water mussels from South America. Proceedings of the United States National Museum. 61(16):1-9 + 3 plates. https://doi.org/10.5479/si.00963801.61-2437.1.

Marshall WB. 1926. New land and fresh-water mollusks from Central and South America. Proceedings of the United States National Museum. 69(12):1-12 + 3 plates. https://doi.org/10.5479/si.00963801.69-2638.1.

Marshall WB. 1927. A new genus and two new species of South American fresh-water mussels. Proceedings of the United States National Museum. 71(6):1-4 + 2 plates. https://doi.org/10.5479/si.00963801.71-2678.1.

Marshall WB. 1930. Type of Anodontites Bruguière. Nautilus 43(4)128-130.

Marshall WB. 1931. Ruganodontites, a new subgenus of South American pearly, fresh-water mussels. Nautilus 45(1):16-20.

Gronovius LT. 1781. Zoophylacium Gronovianum, etc. p. 260. https://doi.org/10.5962/bhl.title.115893.

Modell H. 1942. Das naturliche system der Najaden. Arch. fur Mollusk. 74:161-191.

Morrison JPE. 1943. Two new Orinoco unionids, with notes on Unio granadensis Lea and U. patulus Lea. Nautilus. 57(1):14-16 + 2 plates.

Olsson AA, Wurtz CB. 1951. New Columbian naiades, with observations on other species. Notulae Nature 239:1-9.

Parodiz JJ, Bonnetto AA. 1962. Taxonomy and zoogeographic relationships of the South American Naiades (Pelecypoda: Unionacea and Mutelacea). Malacologia 1(2):179-213.

Pilsbry HA, Olsson AA. 1944. A Venezuelan species of Fossula. Nautilus. 57(3):89, plate 10.

Rochebrune AT. de. 1881. Sur Quelques especes du Haut-Senegal. Bull. Soc. Pilom. 33-35.

Schumacher FC. 1817. Essai d’un nouveau système des habitations des vers Testaces. Copenhagen 1-287 + 22 plates. https://doi.org/10.5962/bhl.title.35863.

Simpson CT. 1900. Synopsis of the naiades, or pearly fresh-water mussels. Proceedings of the United States National Museum. 22(1205):501-1044. https://doi.org/10.5479/si.00963801.22-1205.501.

Simpson CT. 1914. A descriptive catalogue of the naiades, or pearly fresh-water mussels. Parts I-II. Bryant Walker, Detroit, Michigan. xii + 1540 pp. https://doi.org/10.5962/bhl.title.10910.

Sowerby GB. 1869. Mongraph of the genus Mycetopus. in L. Reeve and G.B. Sowerby (eds.) Conchologica Iconica., 20 vols., 2,727 colored plates. Completed by Sowerby. Unios in XVI, Anodontas in XVII. https://doi.org/10.5962/bhl.title.8129.

Spix JB, Wagner JA. 1827. Testacea fluviatilia quae in itinere per Brasiliam collegit. Leipzig. pp. 1-36. https://doi.org/10.5962/bhl.title.59807.

Swainson W. 1840. A treatise on Malacology. London. ?? pp. https://doi.org/10.5962/bhl.title.8027.

von Martens E. 1873. Die Binnenmollusken Venezuelas, etc. Festschrift Gesell. Nat Freunde. pp. 157-225 + 2 plates. https://doi.org/10.5962/bhl.title.10052.

von Martens E. 1900. Biologia Centrali-Americana. Zoologia, Mollusca. ?? pp. https://doi.org/10.5962/bhl.title.730.