Tautonyms of Jousseaume

Just published: a paper on Jousseaume’s tautonyms by Leo van Gemert and myself.

We present a short biography of Félix-Pierre Jousseaume (12 April 1835-3 November 1921) and an addition to his bibliography. He published in total 138 malacological and 21 non-malacological articles or books. In the appendix additional references are listed in comparison with an earlier published preliminary bibliography. Jousseaume received many comments from other malacologists, especially for his tautonyms. Critical remarks from Weinkauff, Tryon, Woodward and Mellvill, and one comment from Jousseaume, are cited.

In total Jousseaume published 28 new species-level taxa as primary, absolute taunonyms (new genus and new species) and 24 secondary ones (22 with a new genus and 2 with a new species name). The virtual tautonyms (with almost identical genus and species names) are not discussed. However, for four taxa of Jousseaume it is unclear if the taxon is a tautonym or a virtual tautonym. In our view the problems were caused by carelessness of Jousseaume. These four taxa are discussed extensively and a conclusion is presented on the correct name. The results are shown in the tables with the original name (invariably the tautonym), source of the original name, and the present view on the taxon with the source and (explanatory) remarks”.

Reference:
Gemert, L.J. van & Breure, A.S.H., 2017. The tautonyms of Jousseaume: a taxonomical studt. – Folia conchyliologica, 42: 14-23.

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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.

Phylogenetic data on Sagdoidea

As an advance online publication, recently appeared the paper by Sei et al. on the phylogenetic relationships within the Sagdoidea.

The abstract reads: “We performed multi-locus, time-calibrated phylogenetic analyses of Jamaican Pleurodontidae to infer their relationships within pulmonate land snails. These analyses revealed that Sagdoidea, with about 200 species in the Caribbean Basin and neighbouring regions, is the sister group of Helicoidea with about 4700 species worldwide and that these superfamilies diverged 61–96 Ma. Morphological disparity in Sagdoidea is similar to that in Helicoidea despite its much lower species richness. Helicoidea originated in the New World and colonized the Old World 46–64 Ma. Pleurodontids and sagdids colonized Jamaica 15.0–18.4 and 12.8–16.5 Ma, respectively, consistent with geological estimates of Jamaican subaerial emergence by mid-Miocene. Allopatric convergence in shell morphologies required caution in using fossils from outside the geographic range of ingroup taxa to calibrate molecular clock estimates. Estimates of ages of clades varied by 24–55%, depending on the calibration points included. We use these results to revise Helicoidea and Sagdoidea. Pleurodontids from Jamaica and the Lesser Antilles were reciprocally monophyletic but other putative pleurodontids grouped basally in Helicoidea as Labyrinthidae (new family), or with Sagdidae. Newly recognized members of Sagdoidea are Solaropsinae and Caracolinae (Solaropsidae), Polydontinae (Sagdidae) and Zachrysiidae (new family). Pleurodontidae is restricted to two subfamilies, Pleurodontinae, in the Lesser Antilles, with Gonostomopsinae, a synonym, and Lucerninae resurrected for the Jamaican endemic genera Lucerna, Dentellaria, Thelidomus and Eurycratera. Lucerna and Dentellaria have been treated as subgenera of Pleurodonte, but rendered it paraphyletic in our analyses”.

This is a nice piece of research for which the authors did extensive DNA research with 3 loci and divergence time analysis. This resulted in a major taxonomical revision of the group, defining the Pleurodontidae and erecting the Labyrinthidae and Zachrysiidae.

Reference:
Sei, M., Robinson, R.G., Geneva, A.J. & Rosenberg, G., 2017. Doubled helix: Sagdoidea is the overlooked sister group of Helicoidea (Mollusca: Gastropoda: Pulmonata). – Biological Journal of the Linnean Society, XX: 1-32 [advance online publication, hence the correct reference will be different].

Achatina fulica: effectiveness of removal methods

The Giant African Snail, Achatina fulica (or Lissachatina f.) is difficult to eradicate once established. This species was introduced in several South American countries and several researchers have made studies on its distribution and possible eradication. One of such studies is by Garcés-Restrepo et al. (2016).

The presence of the giant African snail Achatina fulica (Bowdich 1822) was confirmed in Colombia in 2008. Due to economic and health implications of this species and the difficulties in controlling it, it is essential to establish the relevance of protocols and alternative inexpensive substances used to control the snail. In this research, the effectiveness of manual removal and manual removal with spray of calcium oxide was analyzed. Both techniques had similar efficiencies, so it is recommended that calcium oxide should be implemented only for the disposal of the collected individuals in order to reduce costs and decrease the impact on arthropofauna. In addition, we evaluated the molluscicide ability of commercial sodium hypochlorite, two plant extracts (Tabebuia rosea and Jatropha curcas), and commercial molluscicide (metaldehyde). We found that the three alternative substances were effective as molluscicides, but with lower effectiveness than the commercial substance. Implementation of the extracts of T. rosea and J. curcas is recommended because they have low cost, and do not present negative effects on the environment”.

Reference:
Garcés-Restrepo, M. et al., 2016. Sustancias alternativas para el control del caracol africano (Achatina fulica) en el Valle del Cauca, Colombia. – Biota Colombiana, 17: 44-52.

Morphometrics using photographs

In many cases morphometric studies are done taking landmarks using photographs. There appears to be of distortion, which has been studied in the recent paper by Collins & Gazley (2017).

Most geometric morphometric studies are underpinned by sets of photographs of specimens. The camera lens distorts the images it takes, and the extent of the distortion will depend on factors such as the make and model of the lens and camera and user-controlled variation such as the zoom of the lens. Any study that uses populations of geometric data digitized from photographs will have shape variation introduced into the data set simply by the photographic process. We illustrate the nature and magnitude of this error using a 30-specimen data set of Recent New Zealand Mactridae (Mollusca: Bivalvia), using only a single camera and camera lens with four different photographic setups. We then illustrate the use of retrodeformation in Adobe Photoshop and test the magnitude of the variation in the data set using multivariate Procrustes analysis of variance. The effect of photographic method on the variance in the data set is significant, systematic, and predictable and, if not accounted for, could lead to misleading results, suggest clustering of specimens in ordinations that has no biological basis, or induce artificial oversplitting of taxa. Recommendations to minimize and quantify distortion include: (1) that studies avoid mixing data sets from different cameras, lenses, or photographic setups; (2) that studies avoid placing specimens or scale bars near the edges of the photographs; (3) that the same camera settings are maintained (as much as practical) for every image in a data set; (4) that care is taken when using full-frame cameras; and (5) that a reference grid is used to correct for or quantify distortion”.

There is more that can be wrong than one can suspect, so this might be a useful study for those who are applying morphometrics in their taxonomical work.

Reference:
Collins, K.S. & Gazley, M.F., 2017. Does my posterior look big in this? The effect of photographic distortion on morphometric analyses. – Paleobiology, 43: 508-520.

Galapagos micromolluscs

An interesting paper was recently published by Miquel & Bungartz on micromolluscs found among Galapagos lichens and bryophytes, including a new species.

The new species is a carnivorous snail, Scolodonta rinae, and this family is reported for the firt time from the Galapagos. Other species that were encountered are Pupisoma galapagorum, P. dioscoricola, Tornatellides chathamensis, Helicina sp., and Succinea sp.

The new species was found on the island of Santa Cruz.

Reference:
Miquel, S.E. & Bungartz, F., 2017. Snails found among herbarium specimens of Galapagos lichens and bryophytes, with the description of Scolodonta rinae (Gastropoda: Scolodontidae), a new species of carnivorous micro-mollusk. – Archiv für Molluskenkunde, 146 (1): 173-186.