Gorgeous endemism

The lagoon of Rodrigues Island, located in the heart of the Indian Ocean in the Mascareignes archipelago, houses a very special and beautiful form of Conus pennaceus Born, 1778 called episcopus (Hwass in Bruguiere, 1792).

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Conus pennaceus episcopus is an endemic form with an average size of 35 to 45 mm for adult specimens. It lives in shallow waters, often agitated by strong tidal currents. The brown periostracum, thin and translucent, reveals a tight and dark graphic pattern that contrasts with the usual substrate of the species, a rather coarse clear coral sand. During the day, the species is buried under dead coral blocks or rocks. At night, this cone hunts while moving rapidly on the sand, with a predilection for grassy areas. The species is locally common, and it is not rare to observe groupings of young individuals (I spotted up to 7 cones under the same coral slab). This cone shell is carnivorous, undoubtedly malacophagous, possibly vermivorous and its venom is dangerous for man.

 

The characteristics of the shells from Rodrigues are as follows: a rather stocky form, a dark-brown-black triangular pattern on a white background (sometimes bluish or rosy in young specimens), and the presence of two large and dark spiral stripes, more or less visible according to the textile pattern.

  Conus pennaceus episcopus,  specimens harvested in Rodrigues Island, 2012.  1-2: Large specimens from Anse Bouteille / 3-4: Light pattern from Anse Fémi / 5: Brown pattern from Pointe roche Noire / 6: Small specimen from Port du Sud-Est / 7-9: Average specimens from Anse Quitor / 10-11: Dark pattern from Plaine Corail / 12: Juvenile specimen with rosy background from Rivière Banane.

Conus pennaceus episcopus, specimens harvested in Rodrigues Island, 2012.

1-2: Large specimens from Anse Bouteille / 3-4: Light pattern from Anse Fémi / 5: Brown pattern from Pointe roche Noire / 6: Small specimen from Port du Sud-Est / 7-9: Average specimens from Anse Quitor / 10-11: Dark pattern from Plaine Corail / 12: Juvenile specimen with rosy background from Rivière Banane.

A population living south of the island in a dense sedimentary zone shows a very dark general coloration (particularly young specimens) and a lower average size than other populations. Large specimens (around 50mm) can be observed in the northeast of the island, in a beaten area where the lagoon is narrow.

 Beautiful living Conus pennaceus episcopus in Rodrigues lagoon

This form is scarce in the collections, as collecting is strictly regulated on Rodrigues Island.