The Giant African Snail, Lissachatina fulica, has set foot on the island of Cura??ao. In a just published press release, Mr Gerard van Buurt and Dr Mark Vermeij (CARMABI) announced the discovery of these snails in a garden in Oud Jan Thiel on the island.
CARMABI is now starting investigations about the possible presence of hazardous parasite infections in the animals captured. The extent of the population also has to be established by further research.
This artistic photo of Cerion uva (L.) on Cura??ao was made by Carel de Haseth. It shows how specimens of the same species which are morphologically very differently can occur in the same population.
Would there be an evolutionary advantage of being long and slender in this environment? Do these two forms still reproduce successfully? Just questions of a curious mind???
Cerion uva occurs in massive numbers on Cura??ao, usually not too far from the shore. The shell is very strong, like an army tank protecting its inhabitant.
Even when the snail has died, some can re-use the shell???
This photograph by Mich??le van Veldhoven, taken at the beach of Spaansche Put, is by courtesy of Fran??ois van der Hoeven.
Due to traveling in (the Caribbean and) South America, I haven’t been able to post on my blog. Too busy and with scattered access to webmail only. Writing blogposts in an internet cafe isn’t my favorite.
Just a quick update of my visit to Cura??ao. One of my goals was to gather information on the ecology of Drymaeus elongatus (R??ding, 1789). Gerard van Buurt had observed this species on a number of host plants; together we checked the disjunct occurrence of this species on the island. This species seems to be limited to the southern part of the island. The disjunct distribution may be (in part) be due to the air pollution of the refinery; at least, this is a hypothesis, but difficult to prove empirically.
The other aim was to visit the Christoffelberg reserve, type locality of Guppya moolengraafi Baker, 1924. The excursion to this area was made in conjunction with a local group that weekly explores interesting sites on the island. We collected two samples of leaf litter that need to be sorted out for this tiny snail of only 2 mm.
These photographs of Tudora megacheilos with egg capsules were made on Cura??ao and are courtesy of Gerard van Buurt. Carel de Haseth made the pictures and his work is gratefully acknowledged.
Tudora megacheilos (Potiez & Michaud, 1838), photographed here on the stem of the Caribbean Royal palm, Roystonea oleracea (http://en.wikipedia.org/wiki/Roystonea_oleracea). It is possible that these stems, which seems a preferred habitat for these snails, are used for depositing eggs.
Data and photo courtesy of G. van Buurt, Willemstad, Cura??ao.
Gerard van Buurt sent me some herpetological literature on the foraging of the Puerto Rican Ground Lizard, Ameiva exsul. Lewis (1989) studied the diet selection of this lizard and found that snails made up 17% of the total preys that were identified by diet analysis of this species. Both Subulina octona and Bulimulus guadalupensis (which are common species on Puerto Rico) equally counted for 7% of the preys. Compared to their occurrence in the habitat, snails were overrepresented in the identified preys.
This literature search was triggered by observations on Cura??ao, where Bulimulus guadalupensis is occurring in some gardens in Willemstad. The local lizard Cnemidophorus murinus has been seen catching this snail.
However, the Bulimulus seem to thrive only in gardens where lizards are infrequent. Dogs (especially large dogs) of the garden owners are probably the ‘hidden protectors’ of these snails, as they chase the lizards away and thus create possibilities for the snails to survive.
Lewis, A.R., 1989. Diet selection and depression of prey abundance by an intensively foraging lizard. – Journal of Herpetology 23: 164-170.