Monthly Archives: March 2016

Reproductive cycle in a Cerion species

To illustrate the statement in my previous post of the Cerionidae being well-studied, another paper by Suárez Torres (2015) may be mentioned.

“Gonads of 144 mature specimens of Cerion mumia chrysalis were examined. Between January-December, 2012 were collected 12 specimens per month. Two reproductive cycles were recognized, one from January to April, and another from July to September. Both male and female reproductive cells were observed inside the acini, which defines the species as hermaphrodite. During May-June and subsequently in October-November no follicular activity was observed. In December, the acini decreased notably in size”.

Cerionmummia

It is only by the interests of local malacologists that the biology of species, in this case a Cuban one, can be furthered.

Reference:
Suárez Torres, A., 2015. Ciclo reproductivo de Cerion mumia chrysalis (Pulmonata: Stylommatophora: Cerionidae). – Solenodon 12: 21–27.

Phylogenetic relationships of Cerionidae

A recent paper by Harasewych et al. (2015) explores the phylogenetic relationships within the Cerionidae and its relations to other families. This makes this group one of the more well-studied Neotropical land snails since the work of Uit de Weerd and other recent publications by Harasewych and co-workers.

The new paper is summarized as follows: “Phylogenetic analyses of partial DNA sequences of the mitochondrial COI and 16S rDNA genes derived from Mexistrophia reticulata Thompson, 2011, the type species of the genus Mexistrophia, indicate that this genus is sister taxon to all remaining living Cerionidae, and that the family Cerionidae is most closely related to Urocoptidae. Relationships among representative cerionid taxa are consistent with the zoogeographic hypothesis that Mexistrophia has been isolated from the remaining living Cerionidae since the Cretaceous, and suggest that the near-shore, halophilic habitat that has commonly been associated with this family is likely a Cenozoic adaptation that coincided with the transition from continental to island habitats. The genus Protocerion is described to include the Late Cretaceous species Cerion acherontis Roth and Hartman, 1998, as its retention in Cerion would render this genus paraphyletic”.

Haresewych2015

Reference:
Harasewych, .G., Windsor, A.M., Lopez-Vera, E. & Thompson, F.G., 2015. On the phylogenetic relationships of the genus Mexistrophia and of the family Cerionidae (Gastropoda: Eupulmonata). – The Nautilus 129: 156–162.

New fossil Cerion from Cuba

Fossil Cerionidae are getting more attention, with the recent paper of Harasewych on this subject. Suarez Torres (2015) has now described a new fossil Cerion species from eastern Cuba. The abstract of this paper in Spanish reads: “Cerion petreus sp. nov. is described on fossil state, with type locality at El Guanal, Punta de Maisí, Guantánamo province. This finding allows us to report the occurrence of this genus in Eastern Cuba since Pliocene to Lower Pleistocene”.

Suarez2015

So far, only two fossil species were known. The discovery of this third species is thus a nice addition to our knowledge of this family, which is represented with more than 100 Recent taxa on this island.

Reference:
Suarez Torres, A., 2015. Nueva especie fósil de Cerion Röding, 1798 (Mollusca: Pulmonata: Cerionidae) de Cuba Oriental. – Novitates Caribaea 8: 120–127.

Leap Day new subfamily

Leap Days are relatively rare events, and a paper which appears on a Leap Day is even rarer. However, this year’s Leap Day saw the birth of a new subfamily: Prestonellinae.

ZootaxaPrestonellinae

The name was originally coined by van Bruggen nearly 40 years ago for a  family, but introduced in a way it was not available according to the ICZN rules. Moreover, during these years additional research has shed more light on the systematic position of this group. And thus any day is a good day to make it available under the Code. It happened just to be 29 February 2016.