Monthly Archives: March 2017

The sixth extinction

The decline of molluscan species worldwide is a source of concern as previously has been reported. Now Cowie et al. (2017) have just published a paper in which they present updated data based on additional literature and expert opinions.

“The International Union for Conservation of Nature (IUCN) is the premier global biodiversity conservation organization. Its Red List is a rigorous vehicle for assessing the conservation status of plant and animal species. However, although all animal and bird species recognized by IUCN have been evaluated, only a tiny fraction of invertebrates have been evaluated. As a measure of the numbers of extinct species (since around the year 1500) the Red List is probably quite accurate for birds and mammals, but severely underestimates the numbers for invertebrates. Nonetheless, molluscs stand out as the major group most severely impacted by extinction, with 297 of the 744 animal species listed as extinct in the third issue of the 2016 Red List. Here we review efforts to obtain a more realis- tic, albeit less rigorous, assessment of the numbers of extinct mollusk species. Our approach has been based on bibliographic research and consultation with experts, rather than following the highly detailed but restrictive IUCN Categories and Criteria. In 2009, this led to an assessment that 533 mollusk species were extinct, far more than the number on the Red List. In the present study we revisited this approach and here list 638 species as extinct, 380 as possibly extinct, and 14 as extinct in the wild, a total of 1,032 species in these combined categories, and more than twice as many as listed by IUCN in these categories. However, this approach only considers species for which information is available; it is therefore biased. In a study published in 2015 we developed an alternative approach, based on a random global sample of land snails, and estimated that 3,000–5,100 mollusk species have gone extinct. We review the main reasons for these extinctions: habitat destruction, impacts of introduced species, exploitation and collecting, and, potentially, climate change, and discuss relevant case studies. Oceanic island land snails, especially those of Pacific islands, have suffered the greatest proportion of the extinctions, with some species having gone extinct before being discovered and described scientifically. The Amastridae, an endemic Hawaiian family of 325 recognized species, may have lost all but 18 species. We outline the phases in this catastrophe: 1) pre-human and/or prehistoric extinction, either natural or anthropogenic, with species known only as fossils/subfossils; 2) extinction due to habitat destruction and introduction of a number of alien species by Pacific island people as they settled the islands; 3) extinction due to extensive habitat destruction and introduction of highly destructive invasive alien species following colonization by Westerners; 4) extinction following the advent of large-scale agriculture at the end of the 19th Century, at the time of a major increase in the land snail extinction rate globally; 5) extinction due to increased military activity, tourism, commerce, urbanization and the concomittant rapidly increasing introduction of invasive species after the Second World War. Extrapolating from our assessments of mollusks, we estimate that approximately 7.5–13% of all species have gone extinct since around year 1500. This is orders of magnitude greater than the 860 (0.04% of 2 million) listed as extinct by IUCN (2016). The biodiversity crisis is real”.

The paper has extensive appendices listing all species which are considered as extinct or endangered.

Reference:
Cowie, R.H., Régnier, C., Fontaine, B. & Bouchet, P., 2017. Measuring the sixth extinction: what do mollusks tell us? – The Nautilus, 131: 3-41.

A new Oxychona from Bahia

The Journal of Conchology has recently published some papers relevant to Neotropical land snails. Today, I mention the paper by Porto et al. (2017) about Oxychona.

The abstract reads “A new species of Oxychona was found during excursions to the Michelin Ecological Reserve (13°S), Southern Bahia State (Northeastern Brazil), which comprises an Atlantic Rainforest Conservation Unit. Living snails and empty shells were collected from ground litter accumulations and kept in an artificial environment supplied with local water and sediment, feeding on leaves of almond tree (Terminalia catappa L.). The new species is described and compared with others from adjacent areas of Brazil between 13oS and 15oS including O. bifasciata, O. currani and O. maculata. Oxychona n. sp. is likely to be endemic to Bahia State, thus supporting the biodiversity and rates of endemism of pulmonate molluscs to the Tropical Atlantic Rainforest in Southern America”.

This is a very nice paper as the authors have taken the effort to include a key to Oxychona species. So, although this paper only described a single new species, it still has broader application. The authors also give anatomical and ecological details.

The main author, Beth Neves, was kind enough to send me a short film of a living specimen of the new species, which I’m happy to share here.

Reference:
Porto, R., Rocha Filho, R. da, Johnsson, R. & Neves, E., 2016. New species of Oxychona (Bulimulidae) from Michelin Ecological Reserve (Bahia State, northeastern Brazil. – Journal of Conchology, 42: 105-110.

Two new Urocoptidae from Cuba

Herrera-Uria et al. (2016) described two new species from Isla de la Juventud, Cuba: Cochlodinella pinera and C. pirata. This is the first record of this genus for the island. Besides descriptions also photographs of living material is presented.

Reference:
Herrera-Uria, J, Espinosa, J. & Ortea, J., 2016. Dos nuevas especies del género Cochlodinella Pilsbry & Vanatta, 1898 (Mollusca: Gastropoda: Urocoptidae) de la Isla de la Juventud, Cuba. – Revista de la Academia Canaria de Ciencias, 28: 89-96.

Two papers on CCP snails

Two papers were published, one very recently and one today, related to the material collected by the ‘Comisión Científica del Pacífico’ (CCP). This material was collected during an expedition that lasted from late 1862 to  early 1866 through several Neotropical counties. The material has been deposited in the Madrid museum and was originally studied by Hidalgo (terrestrial molluscs, marine gastropods) and Martínez (marine bivalves).

The terrestrial material has been restudied during a SYNTHESYS project last year, and has resulted in two papers. One dealing with the CCP material and the history of the expedition (Breure & Araujo, 2017), and one dealing with the publication date of Hidalgo’s main paper on the CCP material and related correspondence from him with Crosse in Paris (Breure & Backhuys, 2017).

The link to the first paper is here.

Update:
Due to an unfortunate coincidence at the proof stage (we unexpectedly received only one proof), the following corrections were not made in the published version:
Fig. 3 in the text (page 4) correspond to Fig. 2B
Fig. 4 in the text (page 5) correspond to Fig. 3A
Fig. 5 in the text (page 6) correspond to Fig. 3B
Fig. 6 in the text (page 6) correspond to Fig. 4A
Fig. 7 in the text (page 7) correspond to Fig. 4B
Fig. 8 in the text (page 9) correspond to Fig. 5A
Fig. 9 in the text (page 10) correspond to Fig. 5B
Fig. 10 in the text (page 12) correspond to Fig. 6A
Fig. 11 in the text (page 12) correspond to Fig. 6B
Then, after Fig. 11 in the text, appear Figs. 7A-7B (page 17) that actually correspond to the Figures 7A and 7B; later (page 17) appears Fig. 8G-8H that correspond to Fig. 8.
Finally, Fig. 27H does not depict Bostryx rouaulti as the wrong shell was photographed.

References:
Breure, A.S.H. & Araujo, R. The Neotropical land snails (Mollusca, Gastropoda) collected by the ‘Comisión Científica del Pacífico’. — PeerJ 5: e3065 (142 pp.).
Breure, A.S.H. & Backhuys, W. Science networks in action: the collaboration between J.G. Hidalgo and H. Crosse, and the creation of ‘Moluscos del Viaje al Pacifico, Univalvos terrestres’. — Iberus 35: 11–30.

New records from Baja California

Baja California is an area with a rather scarce land snail fauna, and limited focussed papers in literature. Clark & Salisbury (2016) report on a small collection made during a biodiversity survey inside the Sierra La Laguna Biosphere Reserve, where a new gold mine is being planned.

The snails reported are already known from other localities on the penisula, viz. Naesiotus rimatus (Pfeiffer, 1847), N. spirifer (Gabb, 1868), and Rabdotus sufflatus (Gould in Binney, 1859). A new record is a as yet unidentified Succinea species, which was only collected as dead shell material.

Reference:
Clark, W.H. & Salisbury, R., 2016. New land snail records for Baja California Sur, Mexico. –Conchylia, 47 (3-4): 59-64.

 

New Cuban Urocoptids

In the annual journal of the Santo Domingo natural history museum, a paper appeared in which Herrera-Uria and Espinosa described two new Urocoptidae from Cuba.

schermafbeelding-2017-03-04-om-08-28-19

“Two new species of the genera Liocallonia Pilsbry, 1902 and Tetrentodon Pilsbry, 1903 are described. These species belong to the “Miguel L. Jaume” historical malacological collection housed in the National Museum of Natural History of Cuba. Photographs of the shells are presented”.

schermafbeelding-2017-03-04-om-08-29-15

One of the species is known only by the holotype, the second species is based on twelve specimens.

Reference:
Herrera-Uria, J. & Espinosa, J., 2016. Descripción de dos especies nuevas de Liocallonia y Tetrentodon (Gastropoda: Pulmonata: Urocoptidae) procedentes de la collección “Miguel L. Jaume” del Museo Nacional de Historia Natural de Cuba. – Novitates Caribaea, 10: 31-37.