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| Author(s): |
Bárbara Louise Valentas Romera
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2012-09-21 |
| Examining board members: |
Luiz Ricardo Lopes de Simone;
Flávio Dias Passos;
Sergio Antonio Vanin
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| Advisor: | Luiz Ricardo Lopes de Simone |
| Abstract | |
The family Ungulindae is characterized by gruping species with white and fragiles valves in rounded shape. The genus Diplodonta is the most representative of family and is diagnosed by two cardinal teeth in the hinge, one with bifid appearance. The follow species were found in brazilian coast: Diplodonta portesiana (d\'Orbigny, 1846), Diplodonta guaraniana (d\'Orbigny, 1846), Diplodonta patagônica (d\'Orbigny,1842) and Diplodonta notata Dall, 1901. D. portesiana shows rounded shell; concave dorsal margin; nymph wider than longer, with a short ligament; anatomically shows the greatest proportions of labial palps; small podal gap, with mantle lobes fused in 35% of total lenght; stomach internally covered by three sorting áreas, and a long intestine, performing three loopings. D. guaraniana shows a sub triangular shell; with a nearly straight dorsal margin; long ligament; with a vertical pattern of the microscopical sculpture; anatomically shows the smaller proportion between width and hight of anterior adductor muscle; stomach internally divided by a septum and connected at three lateral ducts of digestive diverticula; short intestine, performing one single loop. D. patagônica shows a elliptical shell; the greatest proportion between the adductor muscles; stomach internally divided by a septum, and covered by one sorting área; intestine performing one loop, and anus opening at ventral third portion of anterior surface of posterior adductor muscle. D. notata shows a oval shell, laterally flattened; nymph short and wide, with a short ligament; concave dorsal margin; anatomically shows a great stomach, with six lateral ducts of digestive diverticula; with the longest intestine of the species, performing one loop. Other species were studied and analized: Phlyctiderma semiaspera (Philippi, 1836); Timothynus rehderi (Altena, 1968); Cyrenoida floridana Dall, 1896 and Cyrenoida sp. nov. P. semiaspera, despite the external similarity with D. guaraniana, shows a inflated shell, externally covered by pustules; anatomically shows adductor muscles with same form and size and three pairs of muscles of the inhalant channel. T. rehderi resembles a D. patagônica, but show a thin and iridescent periostrac; umbones large and tall; with three cardinal teeth in right valve; anatomically show the adductor muscles with the same form and size; small labial palps; inner demibranchs fused in the posterior half and anus opening at middle of suprabranchial chamber. The genus Cyrenoida was first related to brazilian coast; is characterized by the rounded valves, posteriorly pointed, with a small channel; covered by a thin light brown periostrac; in the hinge, a fusion between cardinal and lateral laminar teeth; anatomically shows diferences between the adductor muscles; presence of inhalant and exhalant siphons; stomach elongated, without lateral conection of digestive diverticule ducts. The brazilian Diplodonta species, as the other studied species,can be identified by the combination of shell and anatomical characters. Morphologic comparisions are realized with taxonomic and phylogenetic inferences (AU) | |
| FAPESP's process: | 10/11401-8 - Taxonomic revision of the genus Diplodonta (Bivalvia: Ungulinidae)from brazilian coast. |
| Grantee: | Bárbara Louise Valentas Romera |
| Support Opportunities: | Scholarships in Brazil - Master |