(H.B. Baker, 1930)
Venezuela
Original Description: Tetraplodon stevensi Baker, H.B. 1930:63 in 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.
Type Locality: Rio Yuruari (Essequibo River Dr.), Venezuela.
Lectotype: ANSP 125531a. Baker gave measurements for the “Type” but did not specifically designate a holotype.
Paratypes: ANSP 125531 (3); Senck. Mus. 4661 (1).
Synonymy:
- Castalia stevensi (H.B. Baker, 1930)
- Baker 1930:63; Haas 1931:40; 1966:540.
Castalia orinocensis Morrison, 1943
- Morrison 1943:14, Type locality: Orinoco River, at Maipures, U.S. Colombia. Holotype: USNM 522000. Paratypes: MCZ 167992 (2 specimens). Haas 1966:540.
Description of C. stevensi: “ANSP 125531: four specimens and two odd valves from the Wheatley Collection labeled “C. crosseanus Hidalgo,” and collected by Stevens, Ph.D., from Rio Yuruari (Essequibo drainage), Venezuela.
Shell (pls. XXXII, XXXIII, figs. B): subrhomboid, subsolid, compressed, with quite prominent and straight posterior ridge. Outlines: anterior and narrowly rounded; posterior arched beyond ligament and truncate; dorsal margin convex (although less so than in most species of the genus); ventral slightly so. Beaks are quite low and flattened dorsally, not much anterior to the center. Exterior: epidermis thick, dark olive-green to brownish; radial castae numerous, almost straight and flattened, tending to break up and anastomose into V-shaped ridges on both anterior and posterior slopes, and becoming weaker or disappearing near ventral margin; growth wrinkles coarse, especially toward ventral edge.
Interior: Nacre pearly to bluish, roughened slightly by the radial plicae; anterior adductor scar impressed; posterior superficial; prismatic zone narrow. Hinge: quite shallow; ligament short and only slightly protuberant externally. Right pseudocardinals: two, almost horizontal lamella; dorsal slender and low; ventral much heavier, higher, and usually broken into two accessory points posteriad. Left pseudocardinal: high and lamellar, usually with one accessory posterior point. Laterals: quite short, usually only one in the right valve (one shell has a low accessory ventral ridge) and two in the left; ventral side of the right tooth and dorsal side of the lower left one usually crossed by transverse ridges (absent in type).
This species evidently falls in Simpson’s (1914, Desc. Cat. Naiades, p. 1202) group of T. multisulcatus, although its outline is rather similar to T. schombergianus (Sowerby), which is probably also from the Essequibo drainage. It is nearest crosseanus (Hidalgo) in shape and sculpture, but has flatter, straighter costae, which become irregular at the ends of the shell and scarcely crenulate [on] the ventral margin. T. stevensi is possibly a dwarfed, small stream form of T. schombergianus, but has much sharper, simpler posterior ridge and more regular plicae than those shown by Sowerby (1969, Conch. Icon. XVII, pl. 1, fig. 3).” (Baker, 1930:63-65).
Description of C. orinocensis: “Shell subrhomboid, elliptical, slightly inequalateral, moderately compressed; sculpture of numerous, flat, radiating ridges, crossed by narrow, concentric growth ridges; anterior end evenly rounded. Posterior dorsal slope obliquely truncate; posterior ridge moderate, rounded, ending in a narrowly rounded point a little above the base; dorsal line arched; ventral margin slightly rounded; epidermis olivaceous; laterals long, slightly curved; pseudocardinals irregularly radial, proportionately massive, not linear; nacre white, iridescent behind; anterior adductors, protractor, and retractor cicatrices completely confluent.
The holotype, USNM. No. 522000 was received from Rev. W.H. Fluck, collected on the Orinoco River at Maipures, U.S. Colombia, and measures: Length, 36.6 mm.; height, 24 mm.; diameter, 17.2 mm. The greater degree of inflation, completely confluent anterior muscle scars, and the subradial (massive) pseudocardinals will easily distinguish C. orinocensis from the other members of the group of Castalia multisulcata Hupé.” (Morrison, 1943:14).
Comments: Whether this species is distinct from C. ecarinata Mousson, 1869, or C. schombergiana (Sowerby, 1869) has not yet been determined. The description and figure of the type of C. ecarinata in Haas (1931:40; 89) agree in many ways with C. stevensi. We need to borrow the types of both species and compare them. Haas also lists a specimen of Castalia multisulcatus Hupé, 1857 in the Senckenberg Museum from the Rio Magdalena, Colombia. This should also be looked at.
Specimens Examined: ANSP 125531a (1 Holotype). Yuruari River, a branch of the Orinoco [Essequibo], [Bolivar], Venezuela. Stevens, Ph.D. ANSP 125531 (3 paratypes). Yuruari River, a branch of the Orinoco [Essequibo], [Bolivar], Venezuela. Stevens, Ph.D. INHS 14932 (2). Rio Guarico Barbacoas, Aragua, Venezuela. 5 January 1994. K.S. Cummings, C.A. Mayer & G.B. Mottesi. INHS 14804 (35). Caño Masparito, 1 km NW Libertad, Barinas, Venezuela. 14 January 1993. K.S. Cummings & C.A. Mayer. INHS 14910 (10). Caño Hondo, Agua Negra, Barinas, Venezuela. 14 January 1993. K.S. Cummings & C.A. Mayer. INHS 11888 (7). Rio Tinaco, El Baul, Cojedes, Venezuela. 21 December 1990. L.M. Page, P.A. Ceas, M.E. Retzer & A. Barbarino. INHS 14892 (28). Rio Camoruco, between Estero & Campo Alegre, about 10 km NW Libertad Cojedes, Venezuela. 9 January 1993. K.S. Cummings & C.A. Mayer. INHS 14920 (4). Rio Camoruco, 3 km SE Libertad, Cojedes, Venezuela. 9 January 1993. K.S. Cummings & C.A. Mayer. INHS 7661 (1). Rio Mocapra near La Esperanza, Guarico, Venezuela. 23 January 1986. K.S. Cummings, D.A. Carney & D.C. Taphorn. USNM 383185 (?). Caripe River, Caripito [Monagas], Venezuela. E. Martinez. INHS 14890 (22). Caño el Sardinero, 14 km SE Guanare, Portuguesa, Venezuela. 1 January 1993. K.S. Cummings & C.A. Mayer. INHS 14946 (24). Caño El Sardinero, 14 km SE Guanare Portuguesa, Venezuela. 2 January 1994. K.S. Cummings & C.A. Mayer. INHS 14902 (9). Caño Maraca, Portuguesa, Venezuela. 17 January 1993. L.M. Page. INHS 14904 (4). trib. Caño Igues, 20 km SE Guanare on road to Guanarito Portuguesa, Venezuela. 17 January 1993. L.M. Page. INHS 14931 (9). Caño Igues, La Capilla, Portuguesa, Venezuela. 3 January 1994. K.S. Cummings & G.B. Mottesi. INHS 14939 (38). Caño Maraca, on rd. from Guanare to Guanarito at 60 km marker Portuguesa, Venezuela. 30 December 1993. K.S. Cummings & C.A. Mayer.
Localities of species mentioned above:
- Castalia multisulcatus Hupé, 1857. Type locality: Brazil
Castalia schombergiana Sowerby, 1869. Type locality: British Guiana
Castalia crosseana Hidalgo, 1865. Type locality: Imbabura, Ecuador
Other Castalini from the region:
- Castalia cordata H. and A. Adams, 1857. Type locality: British Guiana
Castalia retusa Hupé, 1857. Type locality: Guiana
Castalia quadrata Sowerby, 1867. Type locality: Guiana
Castalia ecarinata Mousson, 1869. Type locality: Magdalena River, Puerto Nuevo, Colombia
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.