Category Archives: Uncategorized

New Granada

Working on a paper related to Colombian Drymaeus reveals some well-known puzzles about old localities who have not been traced again. In fact, the denomination of the area as “New Grenada” is somewhat of a puzzle, as the meaning of that terminology has shifted over time.
Just out of curiosity, I searched for pictures on “New Grenada” in Google. I found a few, and the shift in what has to be called “New Grenada” is clearly illustrated in the following time-series.

page7_blog_entry33_1

Map of New Grenada
Author: John Pilkerton, 1811. Scale 1:3,400,000. Publshers: Cadell & Davies; Longman, Hurst, Rees, Ome & Brown, London

 

page7_blog_entry33_2

Map of the Kingdom of New Grenada
Author: Hall Sidney, 1827. Scale 1:5,700,000. Publisher: Caddell, London.

 

page7_blog_entry33_3

Map of Venezuela, New Grenada & Equador
Author: Henny Tanner, 1836. Scale 1:6,969,600. Publisher: H.S. Tanner, Philadelphia

The first map shows that New Grenada at one time reached the borders of the Río Marañon, now in the territory of Perú. The last map is especially interesting, since it depicts the situation at the time from which many type material originate, that can still be found in museum collections. What struck me is the very different limitation of the ‘Provinces” or “Departments”. Colombia consisted in the mid-19th century of four parts: Cauca, Cundinamarca, Magdalena and Boyacá. Their geographical limits are, however, rather different from their current, being far more extensive. When interpreting old locality labels this knowledge can be very helpful to pinpoint certain places, which might not be located where one would expect them with today’s map in front.

Just an example of some puzzles that I consider solved, where some geographical knowledge and modern facilities go hand in hand. One of the collectors who travelled extensively through Colombia at that time was Thomas Bland (1809-1885). Many of his collected material was studied by Pilsbry during his work for the Manual of Conchology. But quite often modern authors may be puzzled about some of the places that were visited by Bland.
There were three Drymaeus species with localities originating from Bland that, at first, I was unable to locate. “Between Salamina and Cabuyal, west of Ervé” was one of them, a locality reported for D. bogotensis (Pfeiffer). I looked up Ervé in the GNS gazetteer but nothing turned up. On the other hand, Salamina and Cabuyal – though not sounding like common names – turned up many times from different parts of Colombia. I decided to leave it and went on with my revision.
Another puzzling locality was “near Santa Ana”, type locality of D. decoratus goniobasis Pilsbry, based on material collected by Bland. When I looked up “Santa Ana” in the gazetteer, many places of that name turned up from all over the country.
Finally, I came to D. geometricus (Pfeiffer), for which Pilsbry had another locality from Bland: “Forests in the mountains below Ervé, on the road to Santa Ana”. I’m unaware if there has anything been published about the journeys of Bland in Colombia, but now I had three parts of a puzzle and I decided to find some solution. First the place “Ervé”. This is a highly unusual spelling in Spanish, so it could be phonetical. I decided to look for “erve” in the GNS database, but not with “starts with” option enabled, but with the “contains” option instead. It turned up 6 names, of which 3 could be skipped right away. I ended up with “Páramo de Herveo” and two variants of the populated place “Herveo”, all at or very close to 05° 05′ 00″ N 075° 10′ 00″ W, which is in Dept. Tolima. The first puzzle bit was in place.
The next step was to find Santa Ana, which could not be far away. When I scrutinized the list of names I did not find a place with a modern name that seemed logical to me. Then I was struck by the name Falán in the list, with a variant name Santa Ana, and located 25 km ENE of Herveo. That seemed logical to me, both places are in the region of Fresno in the upper Magdalena valley, from which the species have been reported.
Then finally Salamina and Cabuyal. With the location of Herveo in mind I looked through all the records for these names in the GNS gazetteer. Salamina is in Dept. Caldas, nearly 50 km NW of Herveo. And there is a “Quebrada Cabuyal” in Tolima, 60 km SE of Herveo. Both places are marked with red in the map below, while the three localties of the Drymaeus species mentioned are marked with yellow. Three species finally found their home.

page7_blog_entry33_4

This post was originally published in my previous blog in November 2007; thanks to the WaybackMachine I’m able to re-publish it here.

Brazilian biodiversity

Salvador just published an analytical paper on the diversity of Brazilian land snails.

Brazil is a megadiverse country for many (if not most) animal taxa, harboring a signifi- cant portion of Earth’s biodiversity. Still, the Brazilian land snail fauna is not that diverse at first sight, comprising around 700 native species. Most of these species were described by European and North American naturalists based on material obtained during 19th-century expeditions. Early 20th century malacologists, like Philadelphia-based Henry A. Pilsbry (1862–1957), also made remarkable contributions to the study of land snails in the country. From that point onwards, however, there was relatively little interest in Brazilian land snails until very recently. The last decade sparked a renewed enthusiasm in this branch of malacology, and over 50 new Brazilian species were revealed. An astounding portion of the known species (circa 45%) presently belongs to the superfamily Orthalicoidea, a group of mostly tree snails with typically large and colorful shells. It has thus been argued that the missing majority would be comprised of inconspicuous microgastropods that live in the undergrowth. In fact, several of the species discovered in the last decade belong to these “low-profile” groups and many come from scarcely studied regions or environments, such as caverns and islands. These places still undoubtedly hide many surprises for malacologists and there is still a long way to go until we have a good understanding of the terrestrial gastropod fauna in Brazil. The science behind this venture, however, is still underfunded and moving at a snail’s pace. This is especially unsettling, as land snails are deemed one of the animal groups most vulnerable to extinction, and the overly-exploited natural environments in Brazil might not last long, especially considering the country’s recent environmentally harmful policies.

Schermafbeelding 2019-11-11 om 10.15.35

It is clear that the Brazilian malacologists community is the most active one on the continent with regard to the group under discussion. My feeling is that, especially in the Andean countries, intensified research could bring much more novelties to light. Given the practical limitations following the implementation of the Nagoya Protocol, field work and anatomical and molecular studies have become impossible. This has serious consequences for modern systematic research. At the same time some journals even do no want to publish now a taxonomic paper without molecular data! It is time that local authorities and malacologists become aware of the need to further the application of modern taxonomic techniques (DNA, CT-scanning) and facilitate the necessary field work for it. They should either become active themselves or co-operate with foreign malacologists that can supply these modern techniques. There are enough signs already of a biodiversity crisis emerging to take urgent action!

Reference:
Salvador, R.B., 2019. Land snail diversity in Brazil. Strombus, 25: 10-20.

New Costa Rican euconulids

Just published: a paper by Barrientos with new data on Costa Rican Euconulidae. The abstract is as follows:

Introduction: The family Euconulidae is circumglobal, but only one subfamily, the Euconulinae, occurs in the American continent. Fourteen native euconulids, in three genera, have been reported from Costa Rica.
Objective: In this paper I describe Tikoconus, a new genus of Euconulinae endemic to Costa Rica.
Methods: I dissected alcohol-preserved euconulids collected in Costa Rica. I took photographs or electron micrographs or drew the shell, external anatomy, reproductive system, mantle cavity organs and radula.
Results: The genus Tikoconus can be recognized by its semislug appearance and very thin and often flexible subglobose to subglobose-depressed external shell. Other distinctive features of the genus are a lack of black dots on the mantle and the presence of at least some dark blotches on the subpedal groove band. Internally, the urethra has a Z-shaped prolongation that almost reaches the mantle collar. The reproductive system has a distinctive external C-shaped penial gland that surrounds half of the penis circumference and is attached to the penis and to the penial caecum, but not connected to them by ducts. Also, there is an internal mono- or bi-lobulated extension in the penis. The epiphallus has a verge that enters into the penis. The penial sheath surrounds part of the penis, the epiphallus base and the penial retractor muscle insertion, but leaves the penial gland and the penis caecum free. The gametolytic gland is absent. I described two new subgenera: Tikoconus with six new species-T. (T.) costaricanus sp.n. (type species), T. (T.) onca sp.n., T. (T.) andresi sp.n., T. (T.) katyae sp.n., T. (T.) alosii sp.n., T. (T.) subsilvanus sp.n.; and Bribriconus with only one species-T. (B.) thompsoni sp.n. All species have restricted distributions and are endemic to particular watersheds, except for T. costaricanus which occurs nearly throughout the central mountains of Costa Rican. This genus inhabits very wet, little disturbed tropical forests from 400 to 2 500 masl on the Atlantic slope and from 760 to 2 500 masl on the Pacific slope. The genus Velifera, the other semislug euconulid reported from Costa Rica, is kept as a valid taxon and I choose the specimen ANSP 48765 as lectotype of Velifera gabbi with the purpose of clarifying the application of the name to a taxon.
Conclusion: A new euconulid genus and seven species were described.

Schermafbeelding 2019-11-08 om 17.21.02Schermafbeelding 2019-11-08 om 17.21.38Schermafbeelding 2019-11-08 om 17.23.34

This is thorough paper on this less-known family which occurs in different Neotropical countries. A key is included for the species of the new genus. The paper provides interesting data on the anatomy and ecology of these species, data which are hardly known for other representatives of this family in the Neotropics.

Reference:
Barrientos, Z., 2019. A new genus of semislugs (Stylommatophora: Euconulidae) from Costa Rica and a review of the genus Velifera (Stylommatophora: Euconulidae). Revista de Biologia Tropical, 67 (6): 1313-1358.

Corona from Peru

A short note was published by Schwabe et al. about the finding of Corona regalis (Hupé, 1857) in Central Peru.

Schermafbeelding 2019-11-04 om 14.02.07

The material contained both dextral and sinistral specimens, and confirmed the eniantomorphism occurring in this species (recently the genetic locus was located in a Lymnaea species).

Reference:
Schwabe, E. et al., 2019. First record from ACP Panguana: The pulmonate genus Corona Albers, 1850. – Spixiana, 41 (1): 8.

El Salvador non-marine molluscs

Ignacio Agudo-Padrón has just published a short paper with a list of land and freshwater species from El Salvador. Although most data are contained in the overview by Thompson (2011), two species are listed now as a new for the territory: Bulimulus corneus (G.B. Sowerby I, 1833) and Orthalicus maclurae Martens, 1893.

Schermafbeelding 2019-10-25 om 07.06.00
The paper is illustrated with several photographs of live snails (Drymaeus discrepans (G.B. Sowerby I, 1833) above) and the species list contains 30 names, based on an inventory made by the government of El Salvador in 2016.

Reference:
Agudo-Padrón, I., 2019. Los moluscos no marinos ocurrentes en El Salvador, América Central: una breve revisión panorámica introductoria de su actual conocimiento. – Bioma (El Salvador), 5: 48–53.
Thompson, F.G., 2011. An annotated checklist and bibliography of the land and freshwater snails of México and Central América. – Bulletin Florida Museum Natural History, 50(1): 1–303.

Photo of the day (181): Rabdotus

Bill Frank and Harry Lee added to their site a record and photo of a live Rabdotus dealbatus (Say, 1821), the so-called Whitewashed Rabdotus.

218rab
This snail was found on grass stalks at the base of a limestone cutting, during light rain, between mile 58 and 59 markers along Interstate 840, Rutherford Co., Tennessee on 7 October 2019 (shell height 14 mm).

Left-right chirality

Dextral and sinistral coiling shells are well known throughout the molluscan phylum, but the genetic mechanism was unresolved so far. Abe & Kuroda have recently published  a paper which answers the question.

Schermafbeelding 2019-10-11 om 10.55.35
Their abstract reads “The establishment of left-right body asymmetry is a key biological process that is tightly regulated genetically. In the first application of CRISP/Cas9 to a mollusc, we show decisively that the actin-related diaphanous gene Lsdia 1 is the single maternal gene that determines the shell coiling direction of the freshwater snail Lymnaea stagnalis. Biallelic frameshift mutations of the gene produced sinistrally coiled offspring generation after generation, in the otherwise totally dextral genetic background. This is the gene sought for over a century. We also show that the gene sets the chirality at the one-cell stage, the earliest observed symmetry-breaking event linked directly to body handiness in the animal kingdom. The early intracellular chirality is superseded by the intercellular chirality during the 3rd cleavage, leading to asymmetric nodal and Pitx expression, and then to organismal body handedness. Thus, our findings have important implications for chromophogenesis in invertebrates as well as vertebrates, including humans, and for the evolution of snail chirality”.

This is a breakthrough that has importance beyond malacology. While it sheds light on the occurrence of sinistrality in certain groups (e.g. Clausiliidae), it doesn’t completely answer the question why it occasionally (or with different frequency) is found found in other groups of snails. Is it just a mutation or is there more at play?
Anyway, since sinistrality is also found in some Neotropical groups, this is an interesting paper.

Reference:
Abe, M. & Kuroda, R., 2019. The development of CRISP for a mollusc establishes the formin Lsida1 as the long-sought gene for snail dextral/sinistral coiling. – Development, 146: dev175976 (7 pp.).