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Molecular data attest to the occurrence of autochthonous daphnia pulex (Crustacea, branchiopoda) populations in Sicily, Italy
Full text linkBiological invasions are known to be among the most important threats to the long-term conservation of native biota, and their effects might be even more difficult to contrast when they are cryptic, i.e., when the non-native invaders cannot be easily recognised based on morphology, and can thus be confused with native taxa. Such cryptic invasions are known to widely occur in the cladoceran genus Daphnia O.F. Müller, 1785, so that the actual distribution and status of most species and lineages need to be checked with a genetic approach. In the frame of this work, we investigated if the Sicilian populations of D. (Daphnia) pulex Leydig, 1860 belonged to the allochthonous North American lineage, which is known to occur in several regions of the Palearctic and Afrotropical biogeographical regions, or rather to the autochthonous European lineage of the species. The molecular results obtained, based on a fragment of the mitochondrial gene encoding for NADH subunit dehydrogenase 5 (ND5), allowed us to rule out the allochthonous status of the species, confirming the presence of autochthonous relictual lineages of D. pulex in Sicily. The native status of these populations is in agreement with their local distribution, limited to natural and poorly-impacted water bodies mostly located in wooded areas at medium and high altitudes. The current local distribution of D. pulex in Sicily is possibly linked to the end of the last glacial maximum and the onset of warmer climatic conditions in the early Holocene, which led the species to take refuge in colder microthermal refugia located at high altitudes, determining their current relictual distribution. se only
First record of arctodiaptomus wierzejskii (Richard, 1888) (Copepoda Calanoida Diaptomidae) from Malta
Full text linkDiaptomid copepods belonging to the genus Arctodiaptomus Kiefer, 1932 were collected in two temporary water bodies in Malta. The morphological identification of the collected specimens proved that they belong to Arctodiaptomus wierzejskii (Richard, 1888) even if a morphological peculiarity pertaining to the morphology of the male right antennule of the Maltese populations was observed and here briefly discussed. This finding constitutes the first record of a calanoid copepod from the inland waters of the Maltese Islands
First report of non-marine ostracods (Crustacea, Ostracoda) from the Dahlak Archipelago (Eritrea), with the description of two new species
Full text linkThe information on Recent non-marine ostracod faunas of the north-eastern part of the Afrotropical region is still limited. Here we report the first record of ostracods from the Dahlak Archipelago, a group of small islands located in the southern part of the Red Sea off the Eritrean coast. Specimens were obtained by hatching in the laboratory of diapausing eggs occurring in dried mud collected in temporary freshwater ponds, following the so-called "Sars' method". A total of five species were found, including two species new to science, of which four belong to the family Cyprididae (Cypris galefensis, Plesiocypridopsis newtoni, Heterocypris sp., and Chrissia martensi n.sp.) and one to the family Ilyocyprididae (Ilyocypris dahlakensis n.sp.). A detailed description of the morphology of valves and soft parts is given, and COX1 sequences were obtained for four species. Cypris galefensis was so far only known for its type locality in Somalia with a population containing both males and females, whereas our samples consisted exclusively of females. Plesiocypridopsis newtoni, a species characterised by a wide geographic distribution and previously known to occur also in the Afrotropical region, shows marked variability in the prehensile palps of males, as evidenced by comparing the specimens from this study with descriptions available in the literature. The genus Heterocypris (with 15 species) and the genera of the two new species described here, Chrissia (with 17 species) and Ilyocypris (with four species), have been previously reported from this biogeographic region as well. The analysed specimens of Chrissia martensi n.sp. were all females, none of which had sperm inside the carapace, indicating the possibility of parthenogenetic reproduction in this species. A peculiar sexual dimorphism in the valve morphology characterises Ilyocypris dahlakensis n.sp., with females having a straight posterior margin, forming a right angle at the ventral anterior edge. Rehydration of dry sediments collected from arid areas where wet periods are short and often unpredictable has proven to be a successful method for describing aquatic invertebrate biodiversity
On the occurrence of the invasive Atlantic blue crab Callinectes sapidus Rathbun 1896 (Decapoda: Brachyura: Portunidae) in Sicilian inland waters
Full text link- The Atlantic blue crab Callinectes sapidus Rathbun 1896 is included among the worst invasive alien species in the Mediterranean Sea. Here we report the finding of the species in two Sicilian rivers, the Irminio and the Imera Meridionale, where it was collected up to 6 km distant from the river mouths. Although several records of the species are already available from Italy, this is the first evidence of the occurrence of this invasive crab this far from the coastline throughout the Country. In the light of the well-known impact of the Atlantic blue crab on the invaded water bodies, the monitoring of the species and appropriate mitigation strategies should be implemented in order to protect the threatened native biota of the Sicilian inland waters
Checklist and distribution of the groundwater crustacean fauna from Sicily, Italy
No full textOwing to the “Racovitzan impediment”, the groundwater fauna of most biogeographical regions is currently inadequately known, thus
hampering our understanding of subterranean biodiversity and its protection. Based on an extensive bibliographical review accompanied
by fieldwork to localize occurrence sites, a checklist of crustacean taxa reported to date from Sicilian groundwater is provided, and their
distribution is described. Among the 63 taxa recorded to date, 43 belong to the class Copepoda (orders Cyclopoida and Harpacticoida), 15
to the class Malacostraca (orders Amphipoda, Bathynellacea, Isopoda, and Thermosbaenacea), and 5 to the class Ostracoda (order Podocopida).
Conversely, to date, no representatives of the copepod order Calanoida nor species of the class Branchiopoda have been recorded
from groundwater habitats on the island. Several taxa require accurate taxonomic revision or are yet to be formally described and are thus
at present left in open nomenclature. Finally, the date of publication of several copepod and amphipod taxa is amended. A high incidence
of stygobites (i.e., obligate groundwater dwellers) has been observed in malacostracans, whereas nearly half of the recorded copepods were
non-stygobites. This pattern is mirrored by the incidence of endemic species, which is higher in malacostracans than in copepods. The only
non-stygobitic crustacean species endemic to Sicily observed in
the frame of the present review is the asellid isopod Proasellus
montalentii. The paucity of information currently available on the
Sicilian groundwater ostracods prevents us from drawing conclusions
regarding this crustacean group. The origin and composition
of Sicilian groundwater crustacean fauna can be explained by considering
three major faunal assemblages: the presence of ancient
paleoendemic taxa, likely of Miocene origin, the colonization of
the groundwater of the island during late Pliocene and Pleistocene
land connections with peninsular Italy, and the direct colonization
of these environments from the sea; no species of African origin
have been discovered to date. Based on currently available data,
the groundwater of southeastern Sicily hosts the highest species
richness and some of the most biogeographically interesting taxa.
Unfortunately, a progressive lowering and salinization of the local
aquifers possibly due to climate change and its overexploitation
threats this fauna, and several taxa are disappearing even before
their discovery and description
Morphological and molecular diversity patterns of the genus Tropodiaptomus Kiefer, 1932 (Copepoda, Calanoida, Diaptomidae) in Thailand
Full text linkTropodiaptomus is one of the most specious genera in the family Diaptomidae, but it is often rare in terms of distribution and abundance. Moreover, Tropodiaptomus species show a noteworthy variability in some of the morphological characters considered of prime importance in diaptomid taxonomy, and the presence of cryptic or pseudocryptic species is likely. Thus, through a geographically-wide sampling in Thailand, we aimed to investigate the local diversity of the genus and to compare the morphological and molecular diversity pattern based on mitochondrial and nuclear genes sequences. DNA taxonomy was also implemented in order to check whether the Tropodiaptomus lineages were independent species according to the “evolutionary genetic species concept”. Six Tropodiaptomus morphospecies were found, three of which are putative species new to Science pending a formal description. The finding of such a high incidence of undescribed species stresses the existence of a significant “Linnean shortfall” affecting Thai diaptomids. The molecular results showed that most of the studied species could be identified consistently with their morphology-based taxonomy. However, Tropodiaptomus vicinus and T. cf. lanaonus showed a high level of genetic diversity, suggesting that traditional morphological techniques might be inadequate for correctly assessing their taxonomical status
The Inland Water Copepod Fauna of a Traditional Rural Landscape in a Mediterranean Island (Crustacea, Copepoda)
Full text linkAlthough the Mediterranean area is a well-known hotspot of biological diversity, the crustacean assemblages inhabiting inland waters of the Mediterranean islands are to date unevenly known, and detailed information is missing for most taxa and areas. In the frame of this paper, we provide a checklist and a characterization of the copepod fauna of the lentic water bodies occurring in a traditional rural landscape of Sicily, where the co-existence of agriculture, woodlands, and pastoral activities lead to the presence of a wide range of different aquatic habitats. Overall, 22 copepod species belonging to the orders Calanoida, Cyclopoida, and Harpacticoida have been
found in the 92 surveyed sites, stressing the conservation value of the area. In the study area, species widespread in the west Palaearctic region co-exist with strictly Mediterranean elements and a small but biogeographically significant group of species with northern or Balkan affinities, which support the role of the investigated area as a refugium for species that colonised Sicily during Pleistocene climate fluctuations and are now restricted to the more wet parts of the island. A single non-native species has been found, and its distribution is currently limited to permanent, man-made reservoirs
Stand out from the crowd: Small-scale genetic structuring in the endemic sicilian pond turtle
Full text linkThe geographical pattern of genetic diversity was investigated in the endemic Sicilian pond turtle Emys trinacris across its entire distribution range, using 16 microsatellite loci. Overall, 245 specimens of E. trinacris were studied, showing high polymorphic microsatellite loci, with allele numbers ranging from 7 to 30. STRUCTURE and GENELAND analyses showed a noteworthy, geographically based structuring of the studied populations in five well-characterized clusters, supported by a moderate degree of genetic diversity (FST values between 0.075 and 0.160). Possible explanations for the genetic fragmentation observed are provided, where both natural and human-mediated habitat fragmentation of the Sicilian wetlands played a major role in this process. Finally, some conservation and management suggestions aimed at preventing the loss of genetic variability of the species are briefly reported, stressing the importance of considering the five detected clusters as independent Management Units
Current Status of and Threats to Sicilian Turtles
Full text linkBased on the critical review of the literature published in the last 22 years, an attempt was made to evaluate the current knowledge gap on the distribution and status of the native Testudines taxa occurring in Sicily (namely Caretta caretta, Emys trinacris, and Testudo hermanni hermanni), as well as the available knowledge of the only non-native species with putative viable populations occurring on the island, i.e., Trachemys scripta. Summarizing the current information, all of the Testudines species occurring in Sicily showed a fragmented and incompletely-known distribution, and only scarce data are available about their phenology. Moreover, despite their inclusion of international and national laws (Bern Convention, CITES, Habitat directive), all three native species are facing several threats (e.g., habitat alteration, the occurrence of invasive species, parasite spillover) leading to a reduction of their populations on the island. Future monitoring programs on the island should be enhanced, with an emphasis on those taxa in decline. Moreover, involve Citizen Science programs should also be implemented in order to increase the awareness of non-experts and facilitate the monitoring task
Range-wide phylogeography and taxonomy of the marine rock pools dweller Tigriopus fulvus (Fischer, 1860) (Copepoda, Harpacticoida)
No full textIn the light of the wide distribution and ecological importance of the genus Tigriopus in coastal rock pool habitats, and of its frequent use in aquaculture and as a model organism, we investigated the identity of the Atlantic–Mediterranean Tigriopus populations and elucidated their taxonomy and patterns of morphological and genetic diversity. In order to reach these goals, an “integrative taxonomy” multisource approach was implemented. First, we investigated the constancy and taxonomical value of the morphological characters currently used to distinguish among the Tigriopus species occurring in the Mediterranean and in Eastern Atlantic area north of the Tropic of Cancer, and checked the actual morphological differences possibly present among topotypical samples of Tigriopus fulvus fulvus (Fischer, 1860) and its two subspecies Tigriopus fulvus adriaticus Van Douwe, 1913 and Tigriopus fulvus algiricus Monard, 1935. Then, we sequenced fragments of mitochondrial (12S) and nuclear (28S) genes. In the frame of this study, different “DNA taxonomy” approaches were implemented in order to check whether the subspecies of Tigriopus fulvus were actually lineages evolving independently, that is, valid species according to the “evolutionary genetic species concept.” The results coherently indicate the presence of a single species, characterized by constant morphology and a noteworthy geographically based genetic structure in the whole study area. No morphological or genetic support was found for the taxa of allegedly subspecific rank within T. fulvus, which are thus to be considered junior synonyms of T. fulvus s.s. Finally, a restricted locus typicus is established for T. fulvus, and a neotype is designated
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