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Jorgen Olesen - One of the best experts on this subject based on the ideXlab platform.
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Lynceus amplopedia sp. nov., A New Laevicaudatan Clam Shrimp with Asymmetrically Modified Thoracopods from Yunnan, China (Crustacea: Branchiopoda).
Zoological studies, 2019Co-Authors: Zandra M S Sigvardt, Jorgen Olesen, D. Christopher Rogers, Xiaoyong Chen, Laorsri SanoamuangAbstract:Laevicaudata has a nearly global distribution, but only a few records from China. We present a new Lynceus (Crustacea: Branchiopoda: Laevicaudata) species, Lynceus amplopedia sp. nov., from Yunnan, China, which shows significant left-right differences in some non-clasper thoracopods. It can be distinguished from all congeners by asymmetrically modified thoracopods III-VI. In the 'explanate modified' side (usually the left side, occasionally the right) the following modifications are present: endites 4, 5, and endopod enlarged (explanate) (thoracopods III and IV); exopod with 14-15 digitiform processes dorsomedially (thoracopods V and VI); and broad muscular basis (thoracopods III-V). The following modifications are seen in the thoracopods of the opposing 'spinose modified' side (usually the right side, occasionally the left): endite 4 with robust, specialized spines medially (thoracopods V and VI); endite 3 elongate protruding (thoracopod VI), and broad muscular basis (thoracopod V). Other unique characters of the new species include: male and female rostrum sinuate, compound eyes protruding, male claspers with endopod constricted, and endite 3 with two scale patches. We suggest the modified thoracopods may be involved in mating and/or respiration. The diversity of Chinese Lynceus is also discussed.
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first molecular phylogeny of Laevicaudata crustacea branchiopoda with description of a new species of lynceus from chile and an updated key to species in the americas
Invertebrate Systematics, 2019Co-Authors: Zandra M S Sigvardt, Christopher D Rogers, Patricio De Los Rios, Ferran Palero, Jorgen OlesenAbstract:The first molecular phylogeny of Lynceus (Crustacea: Branchiopoda: Laevicaudata) is presented together with a description of a new species of Laevicaudatan branchiopod from Chile, Lynceus huentelauquensis, sp. nov. DNA sequences were obtained from six species of Lynceus using freshly collected specimens from Europe, North America, South America, and Australia and combined with GenBank sequences from previous studies. Specimens of the new species were collected from a pool on the Huentelauquen Plains near Huentelauquen City. Our molecular analyses placed L. huentelauquensis, sp. nov. within Lynceus and close to a cluster of Australian species, and revealed morphological misidentifications, cross-contamination, or incorrect upload in earlier GenBank sequences. L. huentelauquensis, sp. nov. is separated from other Lynceus primarily by the morphology of the rostrum and the male claspers. L. huentelauquensis, sp. nov. is the first described Laevicaudatan from Chile, the sixth from South America, and the 13th from the Americas. The morphology of Laevicaudatans from the Americas is reviewed and an updated key to the (male) Lynceidae of the region is provided. Our study highlights the necessity of a revision of Laevicaudata using multiple genetic markers as well as thorough morphological studies on a greater number of taxa. urn:lsid:zoobank.org:pub:9A783D96-B270-40DF-8361-11BA063C9A0F
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Functional morphology of amplexus (clasping) in spinicaudatan clam shrimps (Crustacea, Branchiopoda) and its evolution in bivalved branchiopods: A video-based analysis.
Journal of Morphology, 2017Co-Authors: Zandra M S Sigvardt, D. Christopher Rogers, Jorgen OlesenAbstract:Male clam shrimps (Crustacea: Branchiopoda: Laevicaudata, Spinicaudata, and Cyclestherida) have their first one or two trunk limb pairs modified as "claspers," which are used to hold the female during mating and mate guarding. Clasper morphology has traditionally been important for clam shrimp taxonomy and classification, but little is known about how the males actually use the claspers during amplexus (clasping). Homologies of the various clasper parts ("movable finger," "large palp," "palm," "gripping area," and "small palp") have long been discussed between the three clam shrimp taxa, and studies have shown that only some structures are homologous while others are convergent ("partial homology"). We studied the clasper functionality in four spinicaudatan species using video recordings and scanning electron microscopy, and compared our results with other clam shrimp groups. General mating behavior and carapace morphology was also studied. Generally, spinicaudatan and Laevicaudatan claspers function similarly despite some parts being nonhomologous. We mapped clasper morphology and functionality aspects on a branchiopod phylogeny. We suggest that the claspers of the three groups were adapted from an original, simpler clasper, each for a "stronger" grip on the female's carapace margin: 1) Spinicaudata have two clasper pairs bearing an elongated apical club/gripping area with one setal type; 2); Cyclestherida have one clasper pair with clusters of molariform setae on the gripping area and at the movable finger apex; and 3) Laevicaudata have one clasper pair, but have incorporated an additional limb portion into the clasper palm and bear a diverse set of setae. J. Morphol. 278:523-546, 2017. © 2017 Wiley Periodicals, Inc.
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a new species of lynceus muller 1776 from new caledonia crustacea branchiopoda Laevicaudata from dolines with remarks on zoogeography
European journal of taxonomy, 2016Co-Authors: Jorgen Olesen, Zandra M S Sigvardt, Christine Pollabauer, Christopher D RogersAbstract:A new species of Laevicaudatan branchiopods, L ynceus insularis sp. nov., is described. It is reported from five sinkholes (dolines) in the southern part of New Caledonia. Lynceus insularis sp. nov. is closest to Lynceus species from Australia, but can be separated from these on the basis of clasper morphology and the form of the lamina abdominalis. Lynceus insularis sp. nov. is the first record of a remote insular endemic Laevicaudatan. The habitats of the species may be threatened due to hydrological changes, reduction of water supply, acidification of fresh water, invasive species, and/or mining activities in the vicinity.
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Male claspers in clam shrimps (Crustacea, Branchiopoda) in the light of evolution: a case study on homology versus analogy.
Journal of Experimental Zoology, 2014Co-Authors: Tomonari Kaji, Martin Fritsch, Jorgen Olesen, Martin Schwentner, Stefan RichterAbstract:Male “clam shrimps” possess highly modified first (and second) trunk limbs for clasping the carapace of females during copulation. Claspers are present in all three clam shrimp taxa (Laevicaudata, Spinicaudata, and Cyclestherida) but despite striking similarities in their morphology and function, the matter of their homology is controversial. In this study, we address the question of the homology and evolution of these structures by comparing the developmental transformation of an unspecialized trunk limb into a clasper. In addition, we study the musculature and the nervous system in trunk limbs and claspers using confocal laser scanning microscopy. We establish that most (but not all) of the various parts of the claspers are homologous between clam shrimp taxa. We suggest that a single pair of claspers was already present in the ground pattern of Diplostraca, probably most comparable to those in Cyclestherida. The claspers, therefore, do not represent a case of analogy. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 269–280, 2014. © 2014 Wiley Periodicals, Inc.
Stefan Richter - One of the best experts on this subject based on the ideXlab platform.
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Male claspers in clam shrimps (Crustacea, Branchiopoda) in the light of evolution: a case study on homology versus analogy.
Journal of Experimental Zoology, 2014Co-Authors: Tomonari Kaji, Martin Fritsch, Jorgen Olesen, Martin Schwentner, Stefan RichterAbstract:Male “clam shrimps” possess highly modified first (and second) trunk limbs for clasping the carapace of females during copulation. Claspers are present in all three clam shrimp taxa (Laevicaudata, Spinicaudata, and Cyclestherida) but despite striking similarities in their morphology and function, the matter of their homology is controversial. In this study, we address the question of the homology and evolution of these structures by comparing the developmental transformation of an unspecialized trunk limb into a clasper. In addition, we study the musculature and the nervous system in trunk limbs and claspers using confocal laser scanning microscopy. We establish that most (but not all) of the various parts of the claspers are homologous between clam shrimp taxa. We suggest that a single pair of claspers was already present in the ground pattern of Diplostraca, probably most comparable to those in Cyclestherida. The claspers, therefore, do not represent a case of analogy. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 269–280, 2014. © 2014 Wiley Periodicals, Inc.
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Unraveling the origin of Cladocera by identifying heterochrony in the developmental sequences of Branchiopoda
Frontiers in Zoology, 2013Co-Authors: Martin Fritsch, Olaf Rp Bininda-emonds, Stefan RichterAbstract:Introduction One of the most interesting riddles within crustaceans is the origin of Cladocera (water fleas). Cladocerans are morphologically diverse and in terms of size and body segmentation differ considerably from other branchiopod taxa (Anostraca, Notostraca, Laevicaudata, Spinicaudata and Cyclestherida). In 1876, the famous zoologist Carl Claus proposed with regard to their origin that cladocerans might have evolved from a precociously maturing larva of a clam shrimp-like ancestor which was able to reproduce at this early stage of development. In order to shed light on this shift in organogenesis and to identify (potential) changes in the chronology of development (heterochrony), we investigated the external and internal development of the ctenopod Penilia avirostris and compared it to development in representatives of Anostraca, Notostraca, Laevicaudata, Spinicaudata and Cyclestherida. The development of the nervous system was investigated using immunohistochemical labeling and confocal microscopy. External morphological development was followed using a scanning electron microscope and confocal microscopy to detect the autofluorescence of the external cuticle. Results In Anostraca, Notostraca, Laevicaudata and Spinicaudata development is indirect and a free-swimming nauplius hatches from resting eggs. In contrast, development in Cyclestherida and Cladocera, in which non-swimming embryo-like larvae hatch from subitaneous eggs (without a resting phase) is defined herein as pseudo-direct and differs considerably from that of the other groups. Both external and internal development in Anostraca, Notostraca, Laevicaudata and Spinicaudata is directed from anterior to posterior, whereas in Cyclestherida and Cladocera differentiation is more synchronous. Conclusions In this study, developmental sequences from representatives of all branchiopod taxa are compared and analyzed using a Parsimov event-pairing approach. The analysis reveals clear evolutionary transformations towards Cladocera and the node of Cladoceromorpha which correspond to distinct heterochronous signals and indicate that the evolution of Cladocera was a stepwise process. A switch from a strategy of indirect development to one of pseudo-direct development was followed by a shift in a number of morphological events to an earlier point in ontogenesis and simultaneously by a reduction in the number of pre-metamorphosis molts. A compression of the larval phase as well as a shortening of the juvenile phase finally leads to a precocious maturation and is considered as a gradual progenetic process.
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Unraveling the origin of Cladocera by identifying heterochrony in the developmental sequences of Branchiopoda
Frontiers in Zoology, 2013Co-Authors: Martin Fritsch, Olaf Rp Bininda-emonds, Stefan RichterAbstract:Introduction One of the most interesting riddles within crustaceans is the origin of Cladocera (water fleas). Cladocerans are morphologically diverse and in terms of size and body segmentation differ considerably from other branchiopod taxa (Anostraca, Notostraca, Laevicaudata, Spinicaudata and Cyclestherida). In 1876, the famous zoologist Carl Claus proposed with regard to their origin that cladocerans might have evolved from a precociously maturing larva of a clam shrimp-like ancestor which was able to reproduce at this early stage of development. In order to shed light on this shift in organogenesis and to identify (potential) changes in the chronology of development (heterochrony), we investigated the external and internal development of the ctenopod Penilia avirostris and compared it to development in representatives of Anostraca, Notostraca, Laevicaudata, Spinicaudata and Cyclestherida. The development of the nervous system was investigated using immunohistochemical labeling and confocal microscopy. External morphological development was followed using a scanning electron microscope and confocal microscopy to detect the autofluorescence of the external cuticle.
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The development of the nervous system in Laevicaudata (Crustacea, Branchiopoda): insights into the evolution and homologies of branchiopod limbs and ‘frontal organs’
Zoomorphology, 2013Co-Authors: Martin Fritsch, Jorgen Olesen, Tomonari Kaji, Stefan RichterAbstract:We investigated the development of the external morphology and of the nervous system in Lynceus biformis and Lynceus brachyurus (Laevicaudata, Branchiopoda), by using immunohistochemical methods in combination with a confocal laser scanning analysis. In both Lynceus species, a free-swimming nauplius larva, equipped with three appendages, hatches from resting eggs. Despite their close phylogenetic relationship to each other, considerable differences are present in their external morphology. Hatching L. brachyurus larvae are equipped with a large and flattened labrum, where in contrast, the L. biformis larvae possess a smaller labrum with four conspicuous posteriorly directed spines at its margin. Despite these differences, the development of the nervous system is quite similar in both species. The hatching larvae are equipped with a naupliar nervous system, and only in the more advanced stages, the development of the ventral nerve cord starts. Furthermore, our investigation into the nervous system provided insights into architecture and evolution of protocerebral sensory organs, the dorsal setae field and the dorsal frontal organ, only present in Laevicaudata. The identification of frontal filaments with an associated frontal filament organ in Lynceus revealed—after a comprehensive comparison with other branchiopods—that these organs exist throughout Branchiopoda and are comparable to those in other crustaceans. Additionally, our results of the peripheral nervous system analysis showed that the innervation pattern of the naupliar appendages (antenna and mandible) and the trunk appendages could be serially homologized, despite much difference in gross morphology of these. Based on the innervation pattern of limbs, we suggest that the larval uniramous mandibular palp, found in the larvae of all ‘large’ branchiopods, is largely exopodal of nature (contrary to most earlier statements) and that the endopodite of the trunk limbs consists of only one distal endite-like segment (confirming some earlier statements) and not of three as proposed by others.
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Onychocaudata (Branchiopoda: Diplostraca), a new high-level taxon in branchiopod systematics
Journal of Crustacean Biology, 2013Co-Authors: Jorgen Olesen, Stefan RichterAbstract:The systematics of Branchiopoda has received much attention in recent years, and a full understanding of the higher-level classification seems close. Based on a number of phylogenetic analyses involving both morphological and molecular data, some higher-level taxon names have been resurrected in the last decades (Phyllopoda, Diplostraca, Cladocera, Gymnomera) and new names for new hypotheses have been suggested (Cladoceromorpha). Herein we suggest Onychocaudata n. tax. as a name for a clade consisting of Spinicaudata and Cladoceromorpha. This clade has in various previous publications received much morphological support (telsonal region and compound eye characters) as well as strong molecular support. We also argue that the name Diplostraca is best retained with its original content (‘bivalved branchiopods’) since there is still much evidence (especially morphological) for its monophyly and competing hypotheses, e.g., Notostraca and Laevicaudata as sister taxa, are less well supported.
Alejandro M. Maeda-martinez - One of the best experts on this subject based on the ideXlab platform.
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Large branchiopod assemblages common to Mexico and the United States
Hydrobiologia, 1997Co-Authors: Alejandro M. Maeda-martinez, Hortencia Obregón-barboza, Denton Belk, Henri J. DumontAbstract:We present observations on the frequency of large branchiopod associations found in north-central Mexico, and in Arizona, USA. Of a total of 25 species involved in these assemblages, 12 were common in both areas. Fifty-eight (43.3%) of the ponds in Mexico, and seventy-eight (47%) of those in Arizona had two or more species present. The combinations of species which occurred with highest frequency were Streptocephalus mackini with Thamnocephalus platyurus for Arizona, and T. platyurus, Triops sp., and Leptestheria compleximanus for Mexico. In Mexico, and Arizona, as in many parts of the world, multispecies assemblages of large branchiopods are a common phenomenon. Therefore, the ’common rule‘ of’one-phyllopod-per-habitat‘ advanced by Weise (1964) is inconsistent with field observations. Furthermore, since cases of co-occurrence of two or more congeneric species of Anostraca and Notostraca are not uncommon, generalizations about congeners not coexisting remain applicable only for the Spinicaudata and Laevicaudata. On the basis of the literature, and of observations in the field and in the laboratory, we list potential factors contributing to the co-occurrence of several species within a pond.
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New records of large branchiopods (Branchiopoda: Anostraca, Notostraca, and Spinicaudata) in Mexico
Hydrobiologia, 1997Co-Authors: Alejandro M. Maeda-martinez, Hortencia Obregón-barboza, Humberto García-velazcoAbstract:This paper reports new distribution records of large branchiopods for Mexico following a three year survey of the Baja California peninsula. The occurance of the anostracans Thamnocephalus mexicanus (Linder, 1941) and T. platyurus (Packard, 1877), the notostracan Lepidurus lemmoni (Holmes, 1894), and the spinicaudatans Eulimnadia cylindrova (Belk, 1989) and E. texana (Packard,1871), all represent the first records for the peninsula. An undescribed species of the anostracan genus Streptocephalus is recorded from the state of Baja California (Norte). The occurrence of the notostracan genus Triops and four other anostracan species on the peninsula is also confirmed. The conchostracan Cyclestheria hislopi (Baird, 1859) is recorded from the state of Quintana Roo. The collections of Lepidurus and Cyclestheria are the first records for México. These records increase the number of species of large branchiopods reported fromMéxico to 36: 20 Anostraca, 3 Notostraca, 11 Spinicaudata, and 2Laevicaudata.
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Distribution of species of Anostraca, Notostraca, Spinicaudata, and Laevicaudata in Mexico
Hydrobiologia, 1991Co-Authors: Alejandro M. Maeda-martinezAbstract:We inventorize the known distribution of the species of Anostraca, Notostraca, Spinicaudata, and Laevicaudata present in Mexico. Determinations of the species and their distribution involved: 1) Examination of Mexican collections of phyllopods, 2) Extensive sampling in 17 states, and 3) Study of laboratory cultures. The number of phyllopod species known to occur in Mexico is 27: 14 of Anostraca, including three undescribed species, 1 of Notostraca, 10 of Spinicaudata, and 2 of Laevicaudata. These results also include 44 new state records. The records of Branchinecta packardi are the first for Mexico. Some species have extensive distributions, not limited to Mexico: Streptocephalus mackini, S. texanus, Thamnocephalus platyurus, Triops longicaudatus and Leptestheria compleximanus . The species known only from Mexico are Streptocephalus kargesi, S. moorei, Paralimnetis mapimi , two undescribed species of Branchinecta , and an undescribed species of Streptocephalus . The largest number of species found to occur in the same pond at one time was eight.
Christopher D Rogers - One of the best experts on this subject based on the ideXlab platform.
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first molecular phylogeny of Laevicaudata crustacea branchiopoda with description of a new species of lynceus from chile and an updated key to species in the americas
Invertebrate Systematics, 2019Co-Authors: Zandra M S Sigvardt, Christopher D Rogers, Patricio De Los Rios, Ferran Palero, Jorgen OlesenAbstract:The first molecular phylogeny of Lynceus (Crustacea: Branchiopoda: Laevicaudata) is presented together with a description of a new species of Laevicaudatan branchiopod from Chile, Lynceus huentelauquensis, sp. nov. DNA sequences were obtained from six species of Lynceus using freshly collected specimens from Europe, North America, South America, and Australia and combined with GenBank sequences from previous studies. Specimens of the new species were collected from a pool on the Huentelauquen Plains near Huentelauquen City. Our molecular analyses placed L. huentelauquensis, sp. nov. within Lynceus and close to a cluster of Australian species, and revealed morphological misidentifications, cross-contamination, or incorrect upload in earlier GenBank sequences. L. huentelauquensis, sp. nov. is separated from other Lynceus primarily by the morphology of the rostrum and the male claspers. L. huentelauquensis, sp. nov. is the first described Laevicaudatan from Chile, the sixth from South America, and the 13th from the Americas. The morphology of Laevicaudatans from the Americas is reviewed and an updated key to the (male) Lynceidae of the region is provided. Our study highlights the necessity of a revision of Laevicaudata using multiple genetic markers as well as thorough morphological studies on a greater number of taxa. urn:lsid:zoobank.org:pub:9A783D96-B270-40DF-8361-11BA063C9A0F
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ecology and distribution of large branchiopods crustacea branchiopoda anostraca notostraca Laevicaudata spinicaudata of the eastern cape karoo south africa
ZooKeys, 2016Co-Authors: Annah Mabidi, Matthew S Bird, Renzo Perissinotto, Christopher D RogersAbstract:A survey of the large branchiopod fauna of the Eastern Cape Karoo region of South Africa was undertaken to provide baseline biodiversity information in light of impending shale gas development activities in the region. Twenty-two waterbodies, including nine dams and thirteen natural depression wetlands, were sampled during November 2014 and April 2015. A total of 13 species belonging to four orders were collected, comprising five anostracans, one notostracan, six spinicaudatans and one Laevicaudatan. Cyzicus australis was most common, occurring in 46% of the waterbodies. Species co-occurred in 87% of the waterbodies, with a maximum number of six species recorded from the same waterbody. Our new distribution records for Lynceus truncatus, Streptocephalus spinicaudatus and Streptocephalus indistinctus represent substantial expansions of the previously known ranges for these species. Tarkastad is now the westernmost record for Streptocephalus spinicaudatus, while Jansenville now constitutes the southernmost record for Streptocephalus indistinctus. Large branchiopod distribution data from previous Eastern Cape records were combined with our current data, demonstrating that a total of 23 large branchiopod species have been recorded from the region to date. As the Karoo is one of the few major shale basins in the world where the natural baseline is still largely intact, this survey forms a basis for future reference and surface water quality monitoring during the process of shale gas exploration/extraction.
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a new species of lynceus muller 1776 from new caledonia crustacea branchiopoda Laevicaudata from dolines with remarks on zoogeography
European journal of taxonomy, 2016Co-Authors: Jorgen Olesen, Zandra M S Sigvardt, Christine Pollabauer, Christopher D RogersAbstract:A new species of Laevicaudatan branchiopods, L ynceus insularis sp. nov., is described. It is reported from five sinkholes (dolines) in the southern part of New Caledonia. Lynceus insularis sp. nov. is closest to Lynceus species from Australia, but can be separated from these on the basis of clasper morphology and the form of the lamina abdominalis. Lynceus insularis sp. nov. is the first record of a remote insular endemic Laevicaudatan. The habitats of the species may be threatened due to hydrological changes, reduction of water supply, acidification of fresh water, invasive species, and/or mining activities in the vicinity.
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the lynceid clam shrimps branchiopoda Laevicaudata of thailand with keys to the eurasian species
Journal of Crustacean Biology, 2016Co-Authors: Christopher D Rogers, Nukul Saengphan, Wipavee Thaimuangphol, Laorsri SanoamuangAbstract:Laevicaudatan clam shrimps have been previously reported from Thailand, but were only tentatively identified. We report on two new species of Laevicaudatan clam shrimps from Thailand collected after conducting widespread, intensive surveys across the central region of the country. We present diagnoses for each, with remarks on the Asian taxa. Lynceus spinimanus n. sp. is separated from all congeners by the form of the male claspers, the female rostral morphology, and the unique chitinized and projecting epipod and exopod on the female thoracopod XI. Lynceus planifascius n. sp. is separated from all congeners by the form of the rostrum in both sexes and the form of the male clasper. An identification key to the currently accepted Eurasian Lynceus species is provided.
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review of the large branchiopod crustacean fauna of the indian subcontinent anostraca notostraca Laevicaudata spinicaudata cyclestherida
Journal of Crustacean Biology, 2015Co-Authors: Christopher D Rogers, Sameer M PadhyeAbstract:The large branchiopod crustaceans (fairy shrimp, tadpole shrimp, and clam shrimp) of India have been examined with varying degrees of scientific rigour since the late 1800s. Although 86 nominal species have been reported for India, the validity of many is in question – particularly for the clam shrimp. Most Indian endemic taxa are poorly described; some lack type material or the type material has been lost. Most recent revisions of key groups have made no attempt to validate identifications using existing type material, or even to procure topotype material. Worse, recent reviews treat old synonyms as valid names without any analysis or explanation. We provide a review of the taxa from the Indian subcontinent (Bangladesh, India, Nepal, Pakistan, and Sri Lanka) taking a strongly conservative approach to assessing the reported species. We recognize only 42 species: 16 anostracans, 2 notostracans, 3 Laevicaudatans, 21 spinicaudatans (with reservations), and a single species of cyclestherid. This should establish a base point for future work on the branchiopods of the subcontinent.
Brian V Timms - One of the best experts on this subject based on the ideXlab platform.
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a revision of the australian species of lynceus muller 1776 crustacea branchiopoda Laevicaudata lynceidae
Zootaxa, 2013Co-Authors: Brian V TimmsAbstract:Australia has had two species of Lynceus , L. macleayanus (King, 1855) and L. tatei (Brady, 1886) reported to date, both poorly described and without types, and supposedly both widely distributed. This study establishes neotypes and redescribes each according to modern standards. The present distribution of each is severely restricted by the destruction of temporary aquatic habitats, both in cities and in the country and also misunderstood by the lack of recent collecting in some outlying areas. Detailed study of male first thoracopods, together with an understanding of the form of the head and rostrum, antenna 2 spinal patterns, carapace shape, and the females’ lamina abdominalis, most of which are discontinuously variable, has resulted in the delineation of four more species: L. baylyi sp. nov. in desert rockholes of Western Australia; L magdaleanae sp. nov. mainly in deep gnammas of the WA Wheatbelt and Goldfields but also extending into NT, Qld and SA; L. susanneae sp. nov. of rockholes on the Nullarbor Plain, WA; and L. argillaphilus sp. nov. of the coastal Pilbara, WA. Identification keys are provided for all six species, both males and females.
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an appraisal of the diversity and distribution of large branchiopods branchiopoda anostraca Laevicaudata spinicaudata cyclestherida notostraca in australia
Journal of Crustacean Biology, 2012Co-Authors: Brian V TimmsAbstract:The diversity of large branchiopods in Australia has not be reviewed since 1983 for fairy and brine shrimps (Anostraca), 2005 for clam shrimps (Laevicaudata, Spinicaudata, Cyclestherida), and 1955 for shield shrimps (Notostraca). Presently five genera and 59 species of anostracans are known to occur in Australia (up from three genera and 29 species in 1983), with 35 described species plus five known undescribed species of Branchinella, 18 described plus one known undescribed species of Parartemia, two described species of Streptocephalus, two species of Australobranchipus, and two Artemia. Of these Branchinella clandestina and Streptocephalus queenslandicus could be junior synonyms and hence invalid. A few species are widespread (B. australiensis, B. occidentalis, B. affinis), but the majority are restricted to a state or two and many are localised. All species of Parartemia and a few Branchinella are halobionts, while the remainder live in strictly fresh waters. Debate rages on whether one of the two international species of Artemia are native or introduced. The degree of congeneric occurrences varies between genera and across the continent. The clam shrimp fauna is less well known with at least two species of Lynceus, two of Eocyzicus, six of Caenestheria, two of Caenestheriella, an enigmatic species supposedly belonging to Cyzicus, seven of Limnadia, two of Eulimnadia, eight of Limnadopsis, one of Eoleptestheria, and one of Cyclestheria. Two further species of Lynceus, four of Limandia and four of Limnadopsis are being described. This makes 42 species, up from 26, but descriptive and molecular work in progress suggest many more at least in the four genera being studied (Lynceus, Eocyzicus, Caenestheriella, Limnadia). Eocyzicus parooensis and an undescribed species of Limnadia are halophilic. For the Notostraca, the supposedly widespread Triops australiensis and Lepidurus apus viridis may represent many species separable molecularly.
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a list of the recent clam shrimps crustacea Laevicaudata spinicaudata cyclestherida of australia including a description of a new species of eocyzicus
Records of The Australian Museum, 2005Co-Authors: Stefan Richter, Brian V TimmsAbstract:Since 1855, 28 species of clam shrimps (Laevicaudata, Spinicaudata, Cyclestherida) have been described from Australia, although three have been synonymized. One new species of Eocyzicus is described herein. It has a distinctive rostrum that is slightly different in male and females and the clasper has a three segmented palp. With this new species the Australian fauna comprises 26 valid species of clam shrimps. We provide a list of all described species, including their known localities and a key to the genera of Australian clam shrimps.
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A preliminary analysis of the conchostracans (Crustacea: Spinicaudata and Laevicaudata) of the middle Paroo catchment of the Australian arid-zone
Hydrobiologia, 2002Co-Authors: Brian V Timms, Stefan RichterAbstract:Twelve species in the genera Caenestheria, Caenestheriella, Eocyzicus, Eulimnadia, Limnadia, Limnadopsis , and Lynceus have been collected from intermittent wetlands in the Paroo of northwestern New South Wales and southwestern Queensland. This is the first record of Eocyzicus from Australia. Identifications are partly tentative as the Australian fauna is poorly documented; some species seem to be new. There are many co-occurrences, especially in wetlands connected to others, but generally species are adapted for different ranges of turbidity, salinity and length of the wet phase. The high biodiversity is explained by the presence of many distinct types of wetland, each with its own characteristic species.
