Marine snails from southeastern Brazil

The cruise of the R/V Marion Dufresne (MD55) was a joint project of the Muséum National d’Histoire Naturelle (Paris, France) and the Universidade Santa Úrsula (Rio de Janeiro, Brazil), which took place during May and June, 1987. The researchers on board recovered a vast quantity of deep-water mollusks from the southeastern Brazilian coast. This material remained a long time without many studies.

However, the study of this kind of material has recently increased in priority: a complete knowledge of the deep-water
fauna became imperative for further environmental studies and possible legal protection, since the Brazilian government started the extraction of the “Pré-Sal” (pre-salt) level of petroleum, which is causing major disturbances in depths up to 2000 meters off the southeastern Brazilian coast.

We studied two families of snails until so far, Architectonicidae and Seguenziidae. Ongoing work include other families of Seguenzioidea, the Trochoidea and the Patellogastropoda.


Family Architectonicidae

The Architectonicidae comprises about 140 extant species distributed worldwide, living from shallow to deep waters. Architectonicids are popularly known as “sundials” (sometimes they are also called “staircase shells”) due to the discoid outline of their shells.

We have found 6 species in the MD55 material, including one entirely new species (marked in bold below):

  • Pseudotorinia architae (Costa, 1841): This species has an Amphi-Atlantic distribution (from the Mediterranean to the Azores and from North Carolina to southeastern Brazil).
  • Pseudotorinia phorcysi Cavallari, Salvador & Simone, 2014: This species is known only from Rio de Janeiro  state (its type locality), Brazil, in depths of 430 to 450 meters.
  • Psilaxis clertoni Tenório, Barros, Francisco & Silva, 2011: This species is known from Pernambuco state to Rio de Janeiro, Brazil, in depths of ca. 600 to 700 meters.
  • Solatisonax rudigerbieleri Tenório, Barros, Francisco & Silva, 2011: This species is known from Ceará state to Rio de Janeiro, Brazil, in depths of ca. 260 to 720 meters.
  • Spirolaxis centrifuga (Monterosato, 1890): This species has an Amphi-Atlantic distribution (from the Mediterranean to Madeira and São Tomé and from Texas to southeastern Brazil).
  • Spirolaxis lamellifer (Rehder, 1935): This species has an Amphi-Atlantic and Mediterranean distribution.
Architectonicids from the MD55 expedition. A: Pseudotorinia architae (shell width 2.9 mm). B: Pseudotorinia phorcysi (width 2.7 mm). C: Psilaxis clertoni (width 3.5 mm). D: Solatisonax rudigerbieleri (width 4.3 mm). E: Spirolaxis centrifuga (width 1.6 mm). F: Spirolaxis lamellifer (width 5.8 mm).

Family Seguenziidae

The seguenziids are a group of marine snails of worldwide distribution, mostly living in bathyal depths (between 200–1000 m) on fine sedimentary substrates. The family has a scarce but worldwide fossil record; the oldest known seguenziids stem from the Middle Paleocene of Greenland, but there is also a doubtful record from the Late Cretaceous of Germany. They are very unique animals in showing a perplexing mixture of primitive and derived characters. Seguenziids are common in collections of deep-water mollusks, but never in large numbers and almost never collected alive; therefore, their classification is almost completely based on their shells.

We have found 8 species in the MD55 material, including two entirely new species (marked in bold below):

  • Ancistrobasis costulata (Watson, 1879): This species is known from Georgia, USA, to southern Brazil, in depths of ca. 30 to 1170 meters. This species has lately been considered to be the same (a synonym of) as A. reticulata (Philippi, 1844), a species originally described from fossil material from the Pliocene of Italy. We consider that simply synonymizing these species without a thorough revision of both fossil and recent shells is problematic and, thus, we prefer to stick to the name A. costulata for now.
  • Carenzia carinata (Jeffreys, 1877): This species has an Amphi-Atlantic distribution (from the northern end of the Mid-Atlantic Ridge to the Canary Islands and from Florida, USA, to the southeastern Brazilian coast), in depths of ca. 730 to 3450 meters.
  • Carenzia trispinosa (Watson, 1879): This species is known from North Carolina, USA, to Río de la Plata, Argentina, in depths of ca. 680 to 2360 meters.
  • Hadroconus altus (Watson, 1879): This species is known from Texas, USA, to southeastern Brazil, in depths of ca. 500 to 4200 meters.
  • Halystina umberlee Salvador, Cavallari & Simone, 2014: This species is known only from Espírito Santo (its type locality) and Rio de Janeiro states, Brazil, in depths of 950 to 1550 meters.
  • Seguenzia elegans Jeffreys, 1885: This species is known from Portugal and from Mexico to Argentina, in depths of ca. 1350 to 3450 meters.
  • Seguenzia formosa Jeffreys, 1876: This species is known from Morocco, Cape Verde, and from the USA to southernmost Brazil, in depths of ca. 80 to 3700 meters.
  • Seguenzia triteia Salvador, Cavallari & Simone, 2014: This species is known only from Espírito Santo state (its type locality), Brazil, in depths of 1500 to 1575 meters.

With these 8 species above, there is a new total of 10 seguenziid species known from Brazilian waters. The other two species are Ancistrobasis zumbii Lima, Christoffersen & Barros, 2013 (known from off Alagoas state) and Basilissa discula (Dall, 1889) (known from Texas to Rio de Janeiro).

Seguenziids from the MD55 expedition. A:
Seguenziids from the MD55 expedition. A: Ancistrobasis costulata (shell length 4.0 mm). B: Carenzia carinata (length 2.0 mm). C: Carenzia trispinosa (length 3.6 mm). D: Hadroconus altus (length 6.0 mm). E: Halystina umberlee (length 1.8 mm). F: Seguenzia elegans (length 2.8 mm). G: Seguenzia formosa (length 3.3 mm). H: Seguenzia triteia (length 3.3 mm).

Superfamily Trochoidea

Ongoing work…

  • Solariella carvalhoi Lopes & Cardoso, 1958: This species ranges from Venezuela to southern Brazil, occurring from the surface to up to 350 m deep. THe species shows a good amount of morphological variation in the shell.

Bibliography

The preceding text is a summary of the following papers, where this research was published:

  • CAVALLARI, D.C.; SALVADOR, R.B.; SIMONE, L.R.L. 2013. New records of Pseudotorinia architae (Gastropoda, Architectonicidae) from southeastern Brazil. Strombus 20: 6-11.  [PDF]
  • CAVALLARI, D.C.; SALVADOR, R.B.; SIMONE, L.R.L. 2016. Solariella quadricincta Quinn, 1992 and S. staminea Quinn, 1992 are synonyms of S. carvalhoi Lopes & Cardoso, 1958 from the SW Atlantic (Gastropoda: Solariellidae). Zootaxa 4109(1): 96–100.  [PDF]
  • CAVALLARI, D.C.; SALVADOR, R.B.; SIMONE, L.R.L. 2014. Taxonomical study on the Architectonicidae (Gastropoda, Heterobranchia) collected by the Marion Dufresne (MD55) expedition to SE Brazil. Spixiana 37: 35-43.  [PDF]
  • SALVADOR, R.B.; CAVALLARI, D.C.; SIMONE, L.R.L. 2014. Seguenziidae (Gastropoda: Vetigastropoda) from SE Brazil collected by the Marion Dufresne (MD55) expedition. Zootaxa 3878: 536-550.  [PDF]

The material from the MD55 expedition also included the land snails from Trindade Island, which can be seen [HERE].


Other researchers have also published papers on different molluscan groups recovered by the MD55 expedition. Here are the references for these works:

  • Caecidae: Lima S.F.B.; Simone L.R.L.; Guimarães C.R.P. 2015. Caecidae (Gastropoda) collected by the research vessel Marion-Dufresne in southeastern Brazil. Strombus 22: 1-4.
  • Cancellariidae: Verhecken, A. (1991) Description of two new species of bathyal Cancellariidae (Mollusca, Gastropoda) from off Brazil. Bulletin du Muséum National d’Histoire Naturelle (Zoologie) 12: 547-553.
  • Cypraeoidea: Simone, L.R.L. & Cunha, C.M. 2012. Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda). Zoosystema 34: 745-781.
  • Fissurellidae: Simone, L.R.L. & Cunha, C.M. 2014. Taxonomical study on the mollusks collected in Marion-Dufresne (MD55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda). Zootaxa 3835(4): 437-468.
  • Mitriforms: Simone, L.R.L. & Cunha, C.M. 2012. Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda). Zoosystema 34: 745-781.
  • Muricidae: Houart, R. 1991. The southeastern Brazilian Muricidae collected by RV Marion-Dufresne in 1987, with the description of three new species. The Nautilus 105: 26-37.
  • Naticidae: Simone, L.R.L. 2014. Taxonomic study on the molluscs collected during the Marion-Dufresne expedition (MD55) off SE Brazil: the Naticidae (Mollusca: Caenogastropoda). Zoosystema 36: 563-593.
  • NystiellidaeGarcía, E.F. 2011. A new species of Eccliseogyra (Gastropoda: Nystiellidae) from southeastern Brazil. The Nautilus 125: 167-170.
  • Olividae: Absalão, R.S. & Pimenta, A.D. 2003. A new subgenus and three new species of Brazilian deep water Olivella Swainson, 1831 (Mollusca, Gastropoda, Olivellidae) collected by the RV Marion Dufresne in 1987. Zoosystema 25: 177-185.
  • Pyramidellidae: Pimenta, A.D.; Santos, F.N.; Absalão, R.S. 2011. Taxonomic revision of the genus Eulimella (Gastropoda, Pyramidellidae) from Brazil, with description of three new species. Zootaxa 3063: 22-38.
  • Terebridae: Simone, L.R.L. 1999. Comparative morphology and systematics of Brazilian Terebridae (Mollusca, Gastropoda, Conoidea), with descriptions of three new species. Zoosystema 21: 199-248. / Simone, L.R.L. & CUNHA, C.M. 2012. Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda). Zoosystema 34: 745-781.
  • Triphoridae: Fernandes, M.R. & Pimenta, A.D. 2013. Taxonomic review of Metaxia (Gastropoda: Triphoridae) from Brazil, with description of a new species. Zoologia 28: 819-830. / Fernandes, M.R.; Pimenta, A.D.; Leal, J.H. 2013. Taxonomic review of Triphorinae (Gastropoda: Triphoridae) from the Vitória-Trindade Seamount Chain, southeastern Brazil. The Nautilus 127: 1-18.
  • Volutidae: Leal, J.H. & Bouchet, P. 1989. New deep-water Volutidae from off southeastern Brazil (Mollusca: Gastropoda). The Nautilus 103: 1-12.
  • Xenophoridae: Simone, L.R.L. & Cunha, C.M. 2012. Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda). Zoosystema 34: 745-781.
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