The 4th Expedition to the

St. Brandon Shoal

 Indian Ocean

Finally, on the last day of the expedition, and more or less by chance, the first living Conus lecourtorum was found by Eric le Court himself. Jana subsequently discovered the actual habitat of this species: the animal is living in coarse sand and coral rubble, along the high tide line, dug 10 cm deep in wet sand. This habitat seems unique for the family Conidae, which explains why we never found living animals on three previous expeditions. The family of Conidae comprises roughly 1,000 species worldwide. In addition to five smaller living specimens, we managed to collect a good number of well-preserved dead specimens of this elusive species. Fresh dead Morum lorenzi were collected in shallow water off the beach where the holotype was found in 2011, and the range of this peculiar endemic member of Harpidae could be extended to the entire northern half of the atoll. Living Bistolida piae and B. nanostraca were taken for molecular analysis, which revealed a big distance between these morphological sisters (Meyer, pers. comm. 2015).

 

Manuel Tenorio extracted and studied the radula from one of our specimens of Conus lecourtorum and commented: "A very unusual radular morphology I must say. The tooth exhibits one barb, a pointed blade and what seems to be an external cusp, but no denticles nor serrations. The absence of a shaft fold confirms that it is a member of the Conidae rather than Conilithidae. At this time I am not sure to what species this tooth is similar with, as it appears quite unusual."

 

The material collected during the fourth St. Brandon expedition has been added to the collection of the MSF.  It comprises the full range of endemic shallow water gastropods confined to this atoll, which itself seems to represent a separate faunistic sub-province in the western Indian Ocean.

Conus lecourtorum

Left:  Living animal

Right: Radula tooth (courtesy Manuel Tenorio)

©2020 by Molluscan Science Foundation