Tag Archives: literature

Deroceras in Mexico

Just published a paper by Araiza-Gómez et al. on the distribution in Mexico and phylogeny of three Deroceras species.

“This study reports the current distribution in Mexico of Deroceras laeve (Müller, 1774) and D. invadens Reise, Hutchinson, Schunack and Schlitt, 2011, both previously recorded, and the first records of D. reticulatum (Müller, 1774) in this country. The taxonomic identifications were made on the basis of morphology and DNA sequences of a fragment of the cytochrome oxidase I gene. A phylogenetic analysis by maximum likelihood was carried out in order to support the identification and to explore the association of Mexican specimens. D. reticulatum and D. invadens appear restricted to the central portion of the country while D. laeve is widely distributed. Due to the invasive and pest character of these species, it is important to know their distribution in the country and the possible risk to native fauna and crops”.

Schermafbeelding 2017-11-20 om 15.58.36

This study used only the CO1 marker and suggests that for D. laeve three subgroups may be distinguished. Further studies using other markers and phylogeographical analyses are suggested in the discussion.

Reference:
Araiza-Gómez, V. et al., 2017. The exotic slugs of the genus Deroceras (Agriolimacidae) in Mexico: Morphological and molecular characterization, and new data on their distribution. – American Malacological Bulletin, 35(2): 126-133.

Advertisements

Montagu types

Oliver et al. have just published an impressive paper dealing with re-located type material of Colonel George Montagu (1753-1815).

“A complete list of new molluscan taxa introduced by Col. George Montagu (1753–1815) is presented. The available type material of these taxa are itemised and illustrated. The majority are present in the Royal Albert Memorial Museum & Art Gallery, Exeter with a smaller number in the Natural History Museum, London. The historic background of both collections is reviewed with special reference to the many non-British species spuriously introduced into Testacea Britannica and its Supplement”.

I know that locating historical collections doesn’t sound like rocket-science. but in our discipline where ‘every name counts’ it is really very helpful to have type material from our deceased colleagues available for study. And, of course, the further back in time the more difficult it becomes to locate this material and track its provenance.

In the paper also some Neotropical material turned up, quite unexpected for someone who worked on ‘Testacea Britannica’ (i.c. British shells)!

Here is his Helix detrita Montagu, 1803 not Müller, 1774. It proved to be a specimen of Drymaeus elongatus (Röding, 1789), a West Indian species…

Finally, it’s worth repeating here the last lines of their paper: “It is sad to report that those with a knowledge of historic conchology are diminising in numbers and that curatorial expertise throughout the museum sector is threatening the value and access of many collections”.

Reference:
Oliver PG, Morgenroth H, Salvador A (2017) Type specimens of Mollusca described by Col. George Montagu in the Royal Albert Memorial Museum & Art Gallery, Exeter and The Natural History Museum, London. Zoosystematics and Evolution 93(2): 363-412. https://doi.org/10.3897/zse.93.13073

Phylogenetic data Achatinoidea

Phylogenetic studies tend to disrupt often the taxonomic grouping of snails, especially if it combined with anatomical data. Such a study was undertaken by Fontanilla et al. (2017) and a brief paper gives the first results.

This study presents a multi-gene phylogenetic analysis of the Achatinoidea and provides an initial basis for a taxonomic re-evaluation of family level groups within the superfamily. A total of 5028 nucleotides from the nuclear rRNA, actin and histone 3 genes and the 1st and 2nd codon positions of the mitochondrial cytochrome c oxidase subunit I gene were sequenced from 24 species, representing six currently recognised families. Results from maximum likelihood, neighbour joining, maximum parsimony and Bayesian inference trees revealed that, of currently recognised families, only the Achatinidae are monophyletic. For the Ferussaciidae, Ferussacia folliculus fell separately to Cecilioides gokweanus and formed a sister taxon to the rest of the Achatinoidea. For the Coeliaxidae, Coeliaxis blandii and Pyrgina umbilicata did not group together. The Subulinidae was not resolved, with some subulinids clustering with the Coeliaxidae and Thyrophorellidae. Three subfamilies currently included within the Subulinidae based on current taxonomy likewise did not form monophyletic groups”.

It is clear from this publication that within this superfamily further anatomical and molecular studies are needed, the results of which may drastically alter our current systematic treatment of several families in this group.

Reference:
Fontanilla, I.K. et al., 2017. Molecular phylogeny of the Achatinoidea (Mollusca, Gastropoda). – Molecular Phylogenetics and Evolution, 114: 382-385.

Scavenging by macaws

A peculiar observation, already reported in ornithological literature, was repeatedly found in the scavenging of Megalobulimus shells by the Lear’s macaw, Anordorhynchus leari Bonaparte, 1856. The shells were broken and little pieces were eaten, presumable for the uptake of calcium.

The observations were made in northeastern Brazil.

Reference:
Lima, D.M. et al., 2017. Observation on scavenging events on shells of Megalobulimus (Gastropoda: Pulmonata) by Lear’s macaws. – The Festivus, 49(4): 329-331.

Cuban Callonia

The family Urocoptidae is very species-rich in Cuba, and the genus Callonia is but a small representative of this family, albeit very aesthetically. González-Guillén et al. (2017) just published a paper on this group.

Specimens of all western Cuban species of Callonia are illustrated, together with images of live animals and their habitat, followed by comments about recent field work. The putative relationships among species based on the morphological characteristics of last whorl soluteness and rib shape-orientation could be biased. Seemingly ecologic equivalent pairs C.loweiC.dautzenbergiana and C.elliottiC.gemmata are much alike in external appearance although genetic similarities, which have not yet been assessed, could be higher between species sharing the same range. A co-occurrence of Callonia snails with blackish lichen is discussed, raising the inference that Callonia use lichens as food source”.

These ecological observations are worth to be further explored. The putative hypothesis about the relations between the Callonia species can only be verified with molecular analysis.

Many thanks to Gijs Kronenberg for sharing this interesting paper.

Reference:
González-Guillén et al., 2017. Insights on the genus Callonia (Mollusca: Urocoptidae) from Western Cuba. – The Festivus, 49 (4): 332-338.

Invasive apple snails

This time not a terrestrial but a freshwater topic: apple snails, or the family Ampullariidae.
Joshi et al. have just published a book on the biology and management of invasive species of this group. The book contains 22 chapters, divided into three themes: General aspects of apple snail biology, Country specific reports, and Management and use.

In the second section two chapters deal with Pomacea canaliculata respectively in Argentina and Ecuador.

The Argentinan chapter is written by P.R. Martin et al., the abstract reads “Pomacea canaliculata is in many respects the best known species of apple snails (family Ampullariidae), although the available information is both fragmentary and geographically biased. Most studies in its non-native range have focused on applied aspects in managed or arti cial wetlands in various countries in Southeast Asia. In its natural range the emphasis has been on basic studies of its reproductive biology, ecology and behaviour in populations from small streams at the southernmost extreme of its distribution (Southern Pampas, Argentina). The extreme geographic position and the lotic nature of these populations may have biased some conclusions about the behavioural and ecological traits of P. canaliculata; contemporary evolution and genetic exchange may also have diversi ed these traits in the non-native range. Even though the ecological information from native populations may not be directly applicable elsewhere, it nevertheless remains as a necessary reference to understand the full potential of adaptation and spread of P. canaliculata to new environments around the world. Surprisingly enough, comparative studies of native and non-native populations of Pomacea spp. are almost lacking. This short review focuses on the distribution, thermal biology, aerial respiration, feeding, reproduction, phenotypic plasticity and shell shape of Pomacea canaliculata in its native range in Argentina.

The Ecuadorian chapter is M. Correoso et al.; the abstract is “This article characterises and analyses the presence of the alien invasive species Pomacea canaliculata in Ecuador, a pest present in many countries that has severe impacts on agriculture, human health and the natural environment. For the rst time, a list of the native species of the genus Pomacea in Ecuador is provided, as well as an occurrence map, based on review of existing (but few) bibliographic data, museum collections and recent eld work. There is a lack of information on other mollusc species in Ecuador, but there is the potential for ecological impact of P. canaliculata on the native mollusc fauna, especially other Pomacea species, which may already be in decline. Other biological threats and consequences are considered, highlighting the impacts that the invasion has had in this Andean country. Also, events that have occurred since the detection of the pest are reviewed, in particular, the decisions adopted by the rice agricultural sector in comparison with those reported by other countries facing a similar situation. The epidemiological role of P. canaliculata in Ecuador is analysed following confirmation that P. canaliculata can carry the nematode Angiostrongylus cantonensis, which causes eosinophilic meningitis. Cases of human infection and the possible routes of transmission are discussed, confirming that Ecuador was the first South American country to have cases of the disease. These results are compared with those for the giant African snail (Lissachatina fulica), a mollusc that can also transmit the disease. It is probable that native Pomacea species can also be infected with the nematode. Finally, a wide range of measures and management actions that should be considered, and possibly adopted, by Ecuador are proposed with the goal of controlling this dangerous pest.

Reference:
Joshi, R.C., Cowie, R.H. & Sebastian, L.S., 2017. Biology and management of invasive apple snails. Muõz: Philippine Rice Research Institute, 406 pp. Available at http://tinyurl.com/y8aw4htb

Diversity of molluscs in Tamaulipas, NE Mexico

Correa-Sandoval et al. (2017) published new data on the malacofauna of the Edo. Tamaulipas in northeastern Mexico. The abstract reads “Diversity and biogeography of Mexican terrestrial gastropods is poorly known. The terrestrial mollusks of the Sierra of Tamaulipas were surveyed from October 1988 to November 2005. A total of 482 samples were obtained from 30 localities, characterized with different vegetation types. Thirty-one genera and 46 species belonging to 18 families are recorded. The primary zoogeographical relationships are characterized by the presence of neotropical and neartic affinities (17 species: 37%) and the endemic taxa (11 species: 24%). The family Spiraxidae has the largest number of endemic species (6). The biogeographical value in this area is 3.78”.

Given the excellent work of Thompson with his checklist of Central American non-marine molluscs, I cannot say that I concur with the first sentence of the abstract. But this paper fits in the general picture of our current knowledge; there is a detailed species lists but not an overview of sampled localities.

Reference:
Correa-Sandoval, A. et al., 2017. Diversidad y zoogeografia de los moluscos terrestres de la Sierra de Tamaulipas, Mexico. – Acta Zoologica Mexicana Nueva Serie, 33 (1):76-88.