Possible Poecilogony Due to Discontinuous Multifactorial Inheritance in Some Mediterranean Species of Raphitoma (Mollusca, Conoidea, Raphitomidae)

Abstract

At least 10 pairs of similar, most probably closely related, species of Raphitoma are often sampled in the same Mediterranean localities. In each pair, one member bears a planktotrophic protoconch and the other a lecithotrophic one. We propose that the phenomenon may be attributed to a simple gene that functions in conjunction with others and environmental factors to exhibit a discontinuous multifactorial inheritance leading to poecilogony. Below a threshold, the animals may produce fewer and larger germ cells, giving rise to fewer and larger eggs and large lecithotrophic embryos with large paucispiral protoconch I, while above that threshold, more and smaller germ cells leading to smaller eggs and to planktotrophic larvae with small protoconch I and large multispiral protoconch II. Preliminary measurements are in support of our hypothesis. Analysis of mitochondrial DNA markers as well as interbreeding experiments could bring an end to the existing confusion.

Raphitoma (Gastropoda:Conoidea:Raphitomidae) Species Distributed Along the Turkish Coasts

“…Later on, Cachia, Mifsud, and Sammut (2001) contributed to the knowledge of the Mediterranean Raphitoma species and reported 14 taxa from Maltese Islands, with their descriptive and distributional features. Recently, the Raphitoma species distributed along the Greek Seas have been subjected by Manousis, Kontadakis, Mbazios, Polyzoulis, and Galinou-Mitsoudi (2017) and Manousis, Kontadakis, Mbazios, and Polyzoulis (2018). In the last study were reported 27 species from the Greek coasts.…”