Marian A. Ramos

New Species in the Old World: Europe as a Frontier in Biodiversity Exploration, a Test Bed for 21st Century Taxonomy

The number of described species on the planet is about 1.9 million, with ca. 17,000 new species described annually, mostly from the tropics. However, taxonomy is usually described as a science in crisis, lacking manpower and funding, a politically acknowledged problem known as the Taxonomic Impediment. Using data from the Fauna Europaea database and the Zoological Record, we show that contrary to general belief, developed and heavily-studied parts of the world are important reservoirs of unknown species. In Europe, new species of multicellular terrestrial and freshwater animals are being discovered and named at an unprecedented rate: since the 1950s, more than 770 new species are on average described each year from Europe, which add to the 125,000 terrestrial and freshwater multicellular species already known in this region. There is no sign of having reached a plateau that would allow for the assessment of the magnitude of European biodiversity. More remarkably, over 60% of these new species are described by non-professional taxonomists. Amateurs are recognized as an essential part of the workforce in ecology and astronomy, but the magnitude of non-professional taxonomist contributions to alpha-taxonomy has not been fully realized until now. Our results stress the importance of developing a system that better supports and guides this formidable workforce, as we seek to overcome the Taxonomic Impediment and speed up the process of describing the planetary biodiversity before it is too late.

Living on the mountains: Patterns and causes of diversification in the springsnail subgenus Pseudamnicola (Corrosella) (Mollusca: Caenogastropoda: Hydrobiidae)

Hydrobiidae is one of the largest families of freshwater gastropods comprised of approximately 400 genera and 1000 species. Despite this high level of diversity, most hydrobiid species inhabit fragile ecosystems in restricted distribution areas. In this work, we analyze modes of speciation and causes of diversification in the hydrobiid springsnail subgenus Pseudamnicola (Corrosella). Species of this group typically live in nutrient poor springs and streams and are restricted to mountainous regions of the Iberian Peninsula (Spain) and Southern France. Previous morphological and molecular (based only on the cytochrome c oxidase subunit I (COI) gene) studies revealed 11 nominal Corrosella species. In this study, we enhance published molecular results by generating new data from mitochondrial (16S rRNA and COI) and nuclear ribosomal regions (18S and 28S rRNA) from 50 Corrosella populations. As a result of this study we have identified one new species, making a total of twelve recognized species in the subgenus Corrosella. Our phylogenetic results also reveal the existence of three lineages within the subgenus, and the estimation of time divergence indicates the occurrence of three main speciation events during the upper Miocene to Pleistocene. We test the influence of several geographical and ecological variables and observe that diversification patterns are related to habitat fragmentation rather than environmental conditions. This result suggests that the high level of diversity observed within the subgenus may have resulted from a non-adaptive radiation. The formation of the Iberian Peninsula mountain ranges (the Pyrenees in the north and the Betic Cordillera in the south) and the configuration of the Iberian current hydrographic system played important roles in Corrosella speciation. Additionally, during the Miocene the Iberian Peninsula experienced a gradient of increasing temperature and dryness from north to south, which together with a high level of tectonic activity, may have caused the majority of the diversity found in the southern Iberian Peninsula.

Underestimated diversity of hydrobiid snails. The case of Pseudamnicola (Corrosella) (Mollusca: Caenogastropoda: Hydrobiidae)

The freshwater gastropod genus Pseudamnicola Paulucci, 1878 belongs to the family Hydrobiidae Stimpson, 1865 and has been cited in Europe, Africa and Asia. The Ibero-Balearic region is considered one of the areas showing the greatest diversity of hydrobiids although few works have provided complete morphological descriptions. Seven Pseudamnicola species have been described based only on shells and some features of the male and female genitalia. This paper provides the largest set of anatomical and morphological data currently available for hydrobiids and describes five new species of Pseudamnicola (Corrosella) from the Iberian Peninsula: P. (C.) manueli sp. nov., P. (C.) bareai sp. nov., P. (C.) marisolae, sp. nov., P. (C.) iruritai sp. nov. and P. (C.) andalusica sp. nov. Two further species, P. (C.) luisi Boeters, 1984 and P. (C.) falkneri (Boeters, 1970), whose distribution areas overlap, are re-described for comparison. The new species are morphologically well differentiated, the most satisfactory characters being female and male genitalia, radula and nervous system, and are well supported by molecular data, with genetic distances between 5.39 and 11.15% for the mitochondrial DNA cytochrome c oxidase subunit I sequence. All the species inhabit a mountain region whose tectonic episodes are here invoked to explain the creation of an area of endemisms.

New data on Hydrobiidae systematics: two new genera from the Iberian Peninsula

A deep systematic study of the Spanish hydrobiid fauna is unravelling a more complex group of species than was previously described. The use of different taxonomical and statistical methodologies helps to clarify this old classification. Based on anatomical studies made for the first time on specimens from the type locality of Paludina sturmi (Rosenhauer, 1856), the species is redescribed and transferred to a new genus Boetersiella. The study demonstrates that Horatia (?) sturmi (sensu Boeters, 1988) is a combination of two species belonging to two new, different but closely related genera, B. sturmi and Chondrobasis levantina gen. and sp. nov. A second species for the first genus, B. davisi, is also described. Morphometrical analysis (MANOVA and DFA) combining species of both genera showed clear differences in some shell variables although the most valuable discriminant characters are related to the female and male genital systems and to the size and shape of the osphradium. Boetersiella mainly differs from Chondrobasis in having a simple penis while a small basal penial lobe is present in the second; in addition, the distal seminal receptacle is bigger in Boetersiella and leans over the bursa copulatrix instead of over the renal oviduct as is the case in Chondrobasis. The two new genera differ from Horatia Bourguignat, 1887 in three main characters: the lack of a ctenidium, the presence in the female genitalia of only one seminal receptacle in a distal position and a penis simple (in Boetersiella) or with a small lobe close to its basis (in Chondrobasis). None of these characters are present in the type species Horatia klecakiana (Bourguignat, 1887). Both sets of character/character-states also differ from the other two valvatiform genera described for the Iberian Peninsula, Neohoratia Schütt, 1961 and Tarraconia Ramos and Arconada (in Ramos et al., in press). Comparisons with other European valvatiform genera were made although the lack of accurate anatomical data for most of them prevented any cladistical approach.

Morphological and molecular evidence for cryptic species of springsnails [genus Pseudamnicola (Corrosella) (Mollusca, Caenogastropoda, Hydrobiidae)]

Abstract Several Pseudamnicola (Corrosella) populations of the central and eastern Iberian Peninsula have been ascribed to Pseudamnicola (Corrosella) astieri (Dupuy, 1851), though recent evidence demonstrates the species could be endemic to the departments of Var and Alpes-Maritimes in France. Through the identification of cryptic species using a combined morphological and phylogenetic approach, this paper provides a detailed morphological description of Pseudamnicola (Corrosella) astieri, clarifying its taxonomic boundaries and confirming it as a French endemic. In parallel, by comparing Pseudamnicola (Corrosella) populations from the provinces of Castellón and Valencia in Eastern Spain, it was observed that rather than Pseudamnicola (Corrosella) astieri they represented a new species here described as Pseudamnicola (Corrosella) hauffei sp. n. Among other characters, the two species show marked differences in shell shape, male and female genital systems, radular formula and concentration of the nervous system. Pseudamnicola (Corrosella) hauffei sp. n. was also compared morphologically to another two Pseudamnicola (Corrosella) species living in nearby areas [Pseudamnicola (Corrosella) hinzi Boeters, 1986 and Pseudamnicola (Corrosella) navasiana (Fagot, 1907)], molecularly to Pseudamnicola (Corrosella) falkneri (Boeters, 1970), the type species of the subgenus, and to the rest of the Pseudamnicola (Corrosella) species described so far. Morphological differentiation between the species is supported by a genetic divergence of 7.4% inferred from a partial sequence (658 bp) of the mitochondrial gene cytochrome c oxidase subunit I (COI). On the basis of an average 8% (5.39 to 11.15%) divergence estimated for the COI gene in other Pseudamnicola (Corrosella) species reported in GenBank, the existence of two specific entities is here proposed, which will have impact on conservation policies both in France and in Spain.

Effects of habitat transition on the evolutionary patterns of the microgastropod genus Pseudamnicola (Mollusca, Hydrobiidae)

Molecular phylogenies of extant species are considered effective tools to infer mechanisms of speciation. Here, we benefit from this utility to investigate the evolutionary history of an organismal group linked to different aquatic ecosystems, the microgastropod genus Pseudamnicola (family Hydrobiidae). Previous studies have found around 45 species of the nominal subgenus P. (Pseudamnicola), most of them in coastal stream localities of several Mediterranean islands and mainland territories, whereas only 12 species of the other subgenus, P. (Corrosella), have been collected from springs and headwaters of mountainous regions of the Iberian Peninsula and south of France. As springs often act as isolated habitats affecting dispersion and constraining gene flow, we supposed that the temporal history and mode of diversification of species from both subgenera should differ and therefore be reflected in their phylogenetic patterns. To assess this hypothesis, we performed a molecular phylogeny based on mitochondrial and nuclear DNA sequences and later conducted an independent analysis to examine the potential effect of certain geographic and ecological variables in the genetic divergences of the subgenera. Additionally, we estimated the ancestral area of diversification of both groups. Published anatomical revisions and our molecular analyses suggest that the genus Pseudamnicola should be divided into three genera: the two previous subgenera plus a new one described here. As postulated, the evolution of the spring organisms was strongly related to habitat fragmentation and isolation, whereas dispersal followed by divergence seem to have been the most common speciation processes for euryhaline species inhabiting coastal streams and low river stages in which waters remain connected. On the contrary, rather than habitat fragmentation or dispersion, environmental conditions have played a larger role during the deep divergent split leading to the three genera.