Brazilian Seashells: An Unexplored World

by Jose Coltro
For many years I have been working with Brazilian shells. I remember when I was 5 years old collecting Olivancillaria vesica in Santos - today a very polluted port near Sao Paulo. I started to study Brazilian shells as a serious hobby 15 years ago and since that time I have begun to notice a lot of mistakes in our classifications. Most of our material has been compared with the Caribbean species, by description, photo or drawing, but never by using actual specimens. Lots of absurdities have been printed: for instance, Lange de Morretes, in his catalogue in 1947, declared that Cypraea moneta was found in Salvador! He didn't know that a boat sank last century with lots and lots of this species aboard; the Portuguese used to exchange them with Africans for slaves. Storms brought some of those shells to the beaches and Morretes considered it an normal occurrence!

Thirty-three years later, Professor E.C. Rios, in his first book, Coastal Brazilian Seashells (1970), set out to list the Brazilian species correctly. Rios' book had few photos, but it had much better descriptions than Morretes, who carried no illustrations or descriptions. But Rios compared most of the shells with the Caribbean fauna - the only way known to proceed at that time, but a dangerous practice, because there are common species for both areas; but many species considered to be only Brazilian forms of Caribbean material are really new to science. After another three books (1975, 1985, 1994) Rios still has some mistakes, and mysterious species are still there.

If you collect the Pisania auritula in Aruba and compare it with the specimens found along the coast from Para State (North Brasil) down to Espirito Santo State (Central Brasil), you will see that they are the same species, but south from there, the species that Rios considered the same species has enormous differences. This identical situation commonly occurs with regard to many other species: our Astraea tecta, Phalium granulatum, Cyphoma intermedium, and others. My brother Marcus and I convinced Professor Rios that Cymatium raderi, Phyllonotus occulatus and Oliva circinata are the true species from the Brazilian coast. Rios formerly considered C. raderi to be like a large C. femorale; P. occulatus was P. pomum; and O. circinata was O. sayana or O. reticularis.

Most of the confusion occurs because almost no research is done in Brasil on shells that are not commercially important; whereas there are lots of studies about oysters and mussels, important fisheries products. Nor has there been much medical research done with fresh-water species and their relationship to disease.

Since last century few research boats have dredged our cost looking for shells and there are places, especially in north Brasil, where there has been no research at all. I never saw a single shell dredged off Maranhao - only few shallow water species trawled by nets, never deeper than 50-60 meters. I saw a gorgeous Pleurotomaria adansoniana (and I am not sure about this classification) trawled by a Japanese boat off Para in the COA '88 bourse: either someone's not telling the truth about the provenance or there is something new going on there!

Some good deep water material was found off Sao Paulo state in 1988. Most of the shells were collected from waters 300-600 meters deep. Many species were described, like Thala crassa Simone, 1995; and many others will be described. Even in shallow water there are so many interesting species, especially micro mollusks, to be studied. Just remember, Dr. E. Petuch visited Brasil in 1979 and he found in a few weeks a great number of new species, like Cyphoma macumba (then considered C. gibbosum), Dermomurex oxum, Muricopsis oxossi, the rare volute Plicoliva zelindae, etc., most of them in shallow water in the Abrolhos Archipelago.

Prof. Rios listed in his last book 1574 species of mollusks here. Since his book was published, another 30 or 40 new species were described from the Brazilian coast. Probably with serious work it will be possible to find many more new species.