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Gopal Murugan - One of the best experts on this subject based on the ideXlab platform.
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Studies on Large Branchiopod Biology 4. © 2002 Kluwer Academic Publishers. Printed in the Netherlands.
2016Co-Authors: Gopal Murugan, Ro M. Maeda-martı́nez, Norma YAbstract:Molecular characterization of the tadpole shrimp Triops (Branchiopoda: Notostraca) from the Baja California Peninsula, México: New insights on species diversity and phylogeny of the genu
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co occurrence of two tadpole shrimp Triops cf australiensis branchiopoda notostraca lineages in middle paroo north western new south wales with the first record of Triops hermaphrodites for the australian continent
Australian Journal of Zoology, 2009Co-Authors: Gopal Murugan, Alejandro M Maedamartinez, Hortencia Obregonbarboza, Brian V TimmsAbstract:The only species of the genus Triops in Australia, T. australiensis, is found to reproduce by gonochorism. Morphological and reproductive data and molecular analyses of fragments of mitochondrial genes 12S rRNA (12S) and cytochrome oxidase I (COI) indicate that a Triops population from the middle Paroo in north-western New South Wales is composed of two different entities, Triops cf. australiensis lineage A, and T. cf. australiensis lineage B. Gonad histology in individuals with ovisacs of lineage A revealed no evidence of testicular tissue; however, large testicular lobes were found in individuals with ovisacs of lineage B, indicating that they were anatomically hermaphrodites. This is the first record of Australian hermaphroditic Triops. For each lineage, a single haplotype of each gene was obtained. Molecular genetic distance and phylogenetic analyses confirmed the closer relationship and monophyly of the two lineages with T. australiensis (GenBank) when compared with Triops species from other continents. COI haplotypes of lineage A and lineage B differed by 7.7% from each other and differed by 10.2% and 9.6% from a published T. australiensis sequence, respectively. The 12S haplotypes of lineage A and lineage B differed by 3.3% from each other and differed by 2% and 2.5% from a published T. australiensis sequence, respectively. Our results suggest that the two co-occurring Triops lineages probably represent two species that are distinct from T. australiensis.
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molecular characterization of the tadpole shrimp Triops branchiopoda notostraca from the baja california peninsula mexico new insights on species diversity and phylogeny of the genus
Hydrobiologia, 2002Co-Authors: Gopal Murugan, Alejandro M Maedamartinez, Hortencia Obregonbarboza, Norma Y HernandezsaavedraAbstract:Using sequence analyses of fragments of the small and large subunits of mitochondrial genes 12S and 16S rRNA, we studied the molecular identity of five Triops populations from the Baja California Peninsula, Mexico. Additionally, we explored the phylogeny of the genus by comparing with sequence data from gonochoric T. longicaudatus (Zacatecas, Mexico), commercial Triops kit (U.S.A.), T. ‘granarius’ (Japan), T. cancriformis (Austria), T. australiensis (Australia) and Lepidurus lemmoni (U.S.A.). The 16S fragment was not useful to discriminate the American Triops forms because their sequences were more than 99% similar. Molecular and phylogenetic analyses using the 12S gene fragments, in agreement with previous allozyme studies, indicate that the nominal (morphological) species T. longicaudatus is a mixture of several species such that, of the seven Triops American populations studied, six phylogenetic species can be identified and two morphologically and reproductively highly divergent forms can be grouped into a single monophyletic clade. The molecular data, rather than supporting our previous proposal that the phylogenetic relationships of Triops species could be deduced by similarities in the number of total and legless rings, suggest that T. cancriformis may represent an independent group from the rest of the species in that genus. In spite of detectable differences among American populations, our analyses indicate these represent a single monophyletic group when compared to Triops from outside of the New World.
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reproduction molting and growth of two mexican uniparental forms of the tadpole shrimp Triops branchiopoda notostraca under a recirculating culture system
Hydrobiologia, 2001Co-Authors: Hortencia Obregonbarboza, Alejandro M Maedamartinez, Gopal MuruganAbstract:Two forms (here called short and long) of the tadpole shrimp Triops from the Baja California peninsula (Mexico) exhibit interesting features for aquacultural purposes; rapid growth, early maturation (six days) and uniparental reproduction via cysts (i.e. drought-resistant dormant eggs). The use of Triops for aquaculture depends on the standard production of viable cysts. Basic information on the reproductive potential of Triops is scarce. Using a recirculating system, we studied, through two culture tests, the cyst production, frequency of molting, and growth rate of the two Mexican forms. For each form, individual data were obtained from five specimens in Test 1 over 15 days, and from 10 specimens in Test 2 over 20 days. Hatching response of cysts produced in Test 1 was also studied. The short-form showed a high fecundity depositing groups of cysts from the ovisacs several times a day. The mean cyst production per day was 156–306 (Test 1 & 2), and the mean total cyst production was 2028 (range 728–3193) (Test 1), and 5821 (range 4136–7554) (Test 2). The maximum number of cysts deposited by one short-form individual in a day was 1231 (Test 2). The reproductive performance of the long-form was poor. The mean cyst production per day was only 4.2–7.9 (Test 1 & 2). The short-form molted every 2.5–2.8 days and the long-form molted every 2.8–3.7 days. The mean growth rate calculated from the standard length (mm d−1) of the short-form was 0.43–0.84 (Test 1 & 2), and in the long-form the values were 0.84–1.25 (Test 1 & 2). The poor cyst production of the long-form may be explained by inadequate food resources that did not fulfill the nutritional requirements for reproduction. Given its prolific uniparental reproduction (vs. biparental reproduction), the short-form Triops appears as a good potential candidate for aquaculture.
Michael Korn - One of the best experts on this subject based on the ideXlab platform.
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How threatened are large branchiopods (Crustacea, Branchiopoda) in the Iberian Peninsula?
Hydrobiologia, 2017Co-Authors: Juan García-de-lomas, Michael Korn, Jordi Sala, Miguel Alonso, Margarida Machado, Violeta Barrios, Florent Prunier, Antonio Camacho, Dani Boix, Francisco HortasAbstract:The Iberian Peninsula harbours 24 taxa of native large branchiopods (LBs). Most of them inhabit Mediterranean temporary ponds, which are priority habitats under the EU Habitats Directive. In this work, Iberian LBs were evaluated using IUCN Red List criteria based on geographic range (extent of occurrence, area of occupancy, number of locations, habitat fragmentation and expected decline). Our results show that 46% of the Iberian LBs are threatened: four taxa should be considered as Critically Endangered ( Linderiella baetica , Triops emeritensis , Cyzicus tetracerus and Leptestheria mayeti ), three taxa fall under the category Endangered ( Artemia salina , Tanymastigites lusitanica and Triops vicentinus ) and four species ( Artemia sp. parthenogenetic strains, Branchinecta orientalis, Lepidurus apus and Triops gadensis ) are Vulnerable. Two species ( Phallocryptus spinosus, and Maghrebestheria maroccana ) are considered Near Threatened. Our results highlight the worrying risk of extinction of Iberian LBs at the regional level, mainly related to the disappearance and degradation of their habitats and the relatively low degree of habitat protection. For Iberian endemic species, this evaluation is also valid at the global level and gives strong support for their inclusion in the IUCN Red List.
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molecular phylogeny morphology and taxonomy of moroccan Triops granarius lucas 1864 crustacea notostraca with the description of two new species
Zootaxa, 2016Co-Authors: Michael Korn, Anna K HundsdoerferAbstract:We used three molecular markers to investigate populations of Triops granarius from a study area in western Morocco that had a north-south span of approx. 434 km, the most distant populations situated at more than 470 km distance from each other. Previous studies had already investigated two Triops granarius populations from this region and revealed their affiliation to the major phylogenetic lineage that includes Triops cancriformis. By contrast, based on the geographic position of the type locality and the morphology of the type, Triops granarius s.s. likely belongs to a clade that forms the sister group to American and Australian Triops, i.e. including Triops longicaudatus and Triops australiensis. In the present study a second, hitherto unknown phylogenetic lineage was discovered among Moroccan populations of Triops granarius s.l. Our phylogenetic analyses show that both Moroccan lineages of Triops granarius s.l. represent a pair of genetically and morphologically well differentiated sister species that should be separated from Triops granarius. We therefore formally describe them as two new species, Triops maximus sp. nov. and Triops multifidus sp. nov. The early larval stages of both species show a peculiar morphology with 10 to 15 setae on the exopodite of the 2nd antenna. The number of these setae was generally thought to span five to seven in Notostraca. Despite the fact that the antennal setae form a central part of the main locomotory organ in early instars, we found their number to vary by up to two between body-sides of single individuals.
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sister species within the Triops cancriformis lineage crustacea notostraca
Zoologica Scripta, 2006Co-Authors: Michael Korn, Margarida Machado, Federico Marrone, Jose Luis Perezbote, Margarida Cristo, Luis Cancela Da Fonseca, Anna K HundsdoerferAbstract:301 Korn, M., Marrone, F., Perez-Bote, J. L., Machado, M., Cristo, M., Cancela da Fonseca, L. & Hundsdoerfer, A. K. (2006). Sister species within the Triops cancriformis lineage (Crustacea, Notostraca). — Zoologica Scripta , 35 , 301–322. We investigated the phylogenetic relationships among the three presently recognized subspecies of the tadpole shrimp, Triops cancriformis , using mitochondrial 16S and 12S rDNA sequences. Our results indicate that the taxon is divided into two distinct lineages. One lineage is formed of T. c. cancriformis populations and samples from northern Spain that had been classified as T. c. simplex in the most recent literature. The second lineage comprises all populations of T. c. mauritanicus and northern African populations of T. c. simplex . These two main lineages separated 2.3 to 8.9 million years ago, based on the range of inferred molecular clocks recognized for crustacean mtDNA sequence divergence. Percentages of divergence are in the range reported for recognized species in other notostracan lineages and we therefore propose to recognize them as two species, Triops cancriformis and Triops mauritanicus . The latter would comprise two subspecies in northern Africa, one consisting of the Moroccan populations of the former T. c. mauritanicus , the other comprising the African populations of the former T. c. simplex . It also includes three as-yet unnamed lineages. A comparison of morphological characters with the molecular data revealed that the former T. c. simplex cannot be reliably separated from T. c. cancriformis , using morphological characters that have hitherto been used to distinguish among subspecies of T. cancriformis . Our investigation is the first to demonstrate the presence of T. c. cancriformis in Africa (Tunisia). The genetic haplotypes of these populations are identical with haplotypes also occurring in Central and Western Europe, as well as in Sicily. Therefore, we hypothesize that the African populations of T. c. cancriformis
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evidence for cryptic species in the tadpole shrimp Triops granarius lucas 1864 crustacea notostraca
2006Co-Authors: Michael Korn, Anna K HundsdoerferAbstract:We used three ribosomal DNA markers to investigate the genetic divergence of Triops granarius (Lucas, 1864) populations from Tunisia, Namibia and Japan. The comparison of the genetic distances between these samples and those found among other species of Notostraca (both Triops and Lepidurus) strongly suggests that the three Triops granarius populations investigated belong to different, possibly cryptic species.
Anna K Hundsdoerfer - One of the best experts on this subject based on the ideXlab platform.
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molecular phylogeny morphology and taxonomy of moroccan Triops granarius lucas 1864 crustacea notostraca with the description of two new species
Zootaxa, 2016Co-Authors: Michael Korn, Anna K HundsdoerferAbstract:We used three molecular markers to investigate populations of Triops granarius from a study area in western Morocco that had a north-south span of approx. 434 km, the most distant populations situated at more than 470 km distance from each other. Previous studies had already investigated two Triops granarius populations from this region and revealed their affiliation to the major phylogenetic lineage that includes Triops cancriformis. By contrast, based on the geographic position of the type locality and the morphology of the type, Triops granarius s.s. likely belongs to a clade that forms the sister group to American and Australian Triops, i.e. including Triops longicaudatus and Triops australiensis. In the present study a second, hitherto unknown phylogenetic lineage was discovered among Moroccan populations of Triops granarius s.l. Our phylogenetic analyses show that both Moroccan lineages of Triops granarius s.l. represent a pair of genetically and morphologically well differentiated sister species that should be separated from Triops granarius. We therefore formally describe them as two new species, Triops maximus sp. nov. and Triops multifidus sp. nov. The early larval stages of both species show a peculiar morphology with 10 to 15 setae on the exopodite of the 2nd antenna. The number of these setae was generally thought to span five to seven in Notostraca. Despite the fact that the antennal setae form a central part of the main locomotory organ in early instars, we found their number to vary by up to two between body-sides of single individuals.
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sister species within the Triops cancriformis lineage crustacea notostraca
Zoologica Scripta, 2006Co-Authors: Michael Korn, Margarida Machado, Federico Marrone, Jose Luis Perezbote, Margarida Cristo, Luis Cancela Da Fonseca, Anna K HundsdoerferAbstract:301 Korn, M., Marrone, F., Perez-Bote, J. L., Machado, M., Cristo, M., Cancela da Fonseca, L. & Hundsdoerfer, A. K. (2006). Sister species within the Triops cancriformis lineage (Crustacea, Notostraca). — Zoologica Scripta , 35 , 301–322. We investigated the phylogenetic relationships among the three presently recognized subspecies of the tadpole shrimp, Triops cancriformis , using mitochondrial 16S and 12S rDNA sequences. Our results indicate that the taxon is divided into two distinct lineages. One lineage is formed of T. c. cancriformis populations and samples from northern Spain that had been classified as T. c. simplex in the most recent literature. The second lineage comprises all populations of T. c. mauritanicus and northern African populations of T. c. simplex . These two main lineages separated 2.3 to 8.9 million years ago, based on the range of inferred molecular clocks recognized for crustacean mtDNA sequence divergence. Percentages of divergence are in the range reported for recognized species in other notostracan lineages and we therefore propose to recognize them as two species, Triops cancriformis and Triops mauritanicus . The latter would comprise two subspecies in northern Africa, one consisting of the Moroccan populations of the former T. c. mauritanicus , the other comprising the African populations of the former T. c. simplex . It also includes three as-yet unnamed lineages. A comparison of morphological characters with the molecular data revealed that the former T. c. simplex cannot be reliably separated from T. c. cancriformis , using morphological characters that have hitherto been used to distinguish among subspecies of T. cancriformis . Our investigation is the first to demonstrate the presence of T. c. cancriformis in Africa (Tunisia). The genetic haplotypes of these populations are identical with haplotypes also occurring in Central and Western Europe, as well as in Sicily. Therefore, we hypothesize that the African populations of T. c. cancriformis
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evidence for cryptic species in the tadpole shrimp Triops granarius lucas 1864 crustacea notostraca
2006Co-Authors: Michael Korn, Anna K HundsdoerferAbstract:We used three ribosomal DNA markers to investigate the genetic divergence of Triops granarius (Lucas, 1864) populations from Tunisia, Namibia and Japan. The comparison of the genetic distances between these samples and those found among other species of Notostraca (both Triops and Lepidurus) strongly suggests that the three Triops granarius populations investigated belong to different, possibly cryptic species.
L. Brendonck - One of the best experts on this subject based on the ideXlab platform.
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experimental test of the ecosystem impacts of the keystone predator Triops cancriformis branchiopoda notostraca in temporary ponds
Freshwater Biology, 2016Co-Authors: A. Waterkeyn, Patrick Grillas, L. BrendonckAbstract:Keystone species can influence an ecosystem through a series of trophic (both direct and indirect) and non‐trophic effects. In temporary ponds, tadpole shrimps were recently identified as keystone predators, but the full extent of their ecosystem impact is still poorly known. Using a large‐scale mesocosm experiment, we quantified the impact of different Triops cancriformis densities on ecosystem properties: water quality (including chlorophyll a as measure for phytoplankton biomass) and the diversity and structure of macrophyte and zooplankton communities. Mesocosms of 400 L (1 m² surface) were lined with natural pond sediment of two study ponds differing in their natural Triops densities (Triops‐rich and Triops‐poor pond) and inundated to allow hatching from the egg bank. Afterwards, four Triops density treatments were established in the mesocosms: 0 (control), 5, 25 and 100 Triops per m². After 13 weeks, the two highest Triops densities significantly influenced the ecosystem functioning not only by triggering changes in the diversity and composition of the pond communities but also by affecting water quality through bioturbation. These results confirm that tadpole shrimp can function as ecosystem engineers in temporary ponds and could promote a shift from a clear water to a turbid state through a series of trophic and non‐trophic level effects.
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Constitutive but no Triops-induced differences in bet-hedging strategies for hatching in Daphnia
Hydrobiologia, 2013Co-Authors: A. Waterkeyn, N. Pottelbergh, J. Vanoverbeke, B. Vanschoenwinkel, L. Meester, L. BrendonckAbstract:Since cladocerans from the genus Daphnia are known to have evolved several inducible defenses (morphological and life history shifts) against the notostracan predator Triops , we investigated whether hatching was also altered in response to Triops . We tested whether dormant eggs of Daphnia magna are able to detect Triops cancriformis kairomones in the water as a signal of predation pressure and alter their hatching response accordingly to avoid predation. We predicted that, in the presence of Triops kairomones, hatching fractions might be reduced (postponing hatching to a next growing season) and/or that hatching might peak earlier (increasing chances to reproduce before Triops becomes predatory). We also tested whether this response depended on the origin of the population. Ephippia from three D. magna populations, originating from one permanent lake and two temporary pond systems, were exposed to Triops kairomone and control treatments. We observed significant population differences in hatching patterns, both in terms of the fraction of eggs that hatch as well as the timing of hatching, with evidence for within-season bet-hedging through delayed hatching in the populations inhabiting temporary habitats. However, no indication was found that the populations also adjust their hatching pattern to the presence of Triops kairomones.
Hortencia Obregonbarboza - One of the best experts on this subject based on the ideXlab platform.
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co occurrence of two tadpole shrimp Triops cf australiensis branchiopoda notostraca lineages in middle paroo north western new south wales with the first record of Triops hermaphrodites for the australian continent
Australian Journal of Zoology, 2009Co-Authors: Gopal Murugan, Alejandro M Maedamartinez, Hortencia Obregonbarboza, Brian V TimmsAbstract:The only species of the genus Triops in Australia, T. australiensis, is found to reproduce by gonochorism. Morphological and reproductive data and molecular analyses of fragments of mitochondrial genes 12S rRNA (12S) and cytochrome oxidase I (COI) indicate that a Triops population from the middle Paroo in north-western New South Wales is composed of two different entities, Triops cf. australiensis lineage A, and T. cf. australiensis lineage B. Gonad histology in individuals with ovisacs of lineage A revealed no evidence of testicular tissue; however, large testicular lobes were found in individuals with ovisacs of lineage B, indicating that they were anatomically hermaphrodites. This is the first record of Australian hermaphroditic Triops. For each lineage, a single haplotype of each gene was obtained. Molecular genetic distance and phylogenetic analyses confirmed the closer relationship and monophyly of the two lineages with T. australiensis (GenBank) when compared with Triops species from other continents. COI haplotypes of lineage A and lineage B differed by 7.7% from each other and differed by 10.2% and 9.6% from a published T. australiensis sequence, respectively. The 12S haplotypes of lineage A and lineage B differed by 3.3% from each other and differed by 2% and 2.5% from a published T. australiensis sequence, respectively. Our results suggest that the two co-occurring Triops lineages probably represent two species that are distinct from T. australiensis.
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reproduction of the tadpole shrimp Triops notostraca in mexican waters
Current Science, 2009Co-Authors: Humberto Garciavelazco, Hortencia Obregonbarboza, Carmen Rodriguezjaramillo, Alejandro M MaedamartinezAbstract:The gonadic histology of the tadpole shrimp Triops sp. from 22 Mexican locations was determined using light microscopy to investigate the hermaphroditic tissue. The sex ratio and type of morphotypes were also determined. Short morphotype individuals with ovisacs (58) were hermaphrodites and were recorded from 14 locations. Of the 34 long morphotype individuals with ovisacs, 25 were hermaphrodites recorded from seven locations, whereas nine were females recorded from only three locations. The proportion of males in hermaphrodite populations ranged from zero to 21%. Thus we infer that such populations have an androdioic reproduction. In female populations, it ranged from 50 to 62%; therefore such populations have a gonochoric reproduction.
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molecular characterization of the tadpole shrimp Triops branchiopoda notostraca from the baja california peninsula mexico new insights on species diversity and phylogeny of the genus
Hydrobiologia, 2002Co-Authors: Gopal Murugan, Alejandro M Maedamartinez, Hortencia Obregonbarboza, Norma Y HernandezsaavedraAbstract:Using sequence analyses of fragments of the small and large subunits of mitochondrial genes 12S and 16S rRNA, we studied the molecular identity of five Triops populations from the Baja California Peninsula, Mexico. Additionally, we explored the phylogeny of the genus by comparing with sequence data from gonochoric T. longicaudatus (Zacatecas, Mexico), commercial Triops kit (U.S.A.), T. ‘granarius’ (Japan), T. cancriformis (Austria), T. australiensis (Australia) and Lepidurus lemmoni (U.S.A.). The 16S fragment was not useful to discriminate the American Triops forms because their sequences were more than 99% similar. Molecular and phylogenetic analyses using the 12S gene fragments, in agreement with previous allozyme studies, indicate that the nominal (morphological) species T. longicaudatus is a mixture of several species such that, of the seven Triops American populations studied, six phylogenetic species can be identified and two morphologically and reproductively highly divergent forms can be grouped into a single monophyletic clade. The molecular data, rather than supporting our previous proposal that the phylogenetic relationships of Triops species could be deduced by similarities in the number of total and legless rings, suggest that T. cancriformis may represent an independent group from the rest of the species in that genus. In spite of detectable differences among American populations, our analyses indicate these represent a single monophyletic group when compared to Triops from outside of the New World.
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reproduction molting and growth of two mexican uniparental forms of the tadpole shrimp Triops branchiopoda notostraca under a recirculating culture system
Hydrobiologia, 2001Co-Authors: Hortencia Obregonbarboza, Alejandro M Maedamartinez, Gopal MuruganAbstract:Two forms (here called short and long) of the tadpole shrimp Triops from the Baja California peninsula (Mexico) exhibit interesting features for aquacultural purposes; rapid growth, early maturation (six days) and uniparental reproduction via cysts (i.e. drought-resistant dormant eggs). The use of Triops for aquaculture depends on the standard production of viable cysts. Basic information on the reproductive potential of Triops is scarce. Using a recirculating system, we studied, through two culture tests, the cyst production, frequency of molting, and growth rate of the two Mexican forms. For each form, individual data were obtained from five specimens in Test 1 over 15 days, and from 10 specimens in Test 2 over 20 days. Hatching response of cysts produced in Test 1 was also studied. The short-form showed a high fecundity depositing groups of cysts from the ovisacs several times a day. The mean cyst production per day was 156–306 (Test 1 & 2), and the mean total cyst production was 2028 (range 728–3193) (Test 1), and 5821 (range 4136–7554) (Test 2). The maximum number of cysts deposited by one short-form individual in a day was 1231 (Test 2). The reproductive performance of the long-form was poor. The mean cyst production per day was only 4.2–7.9 (Test 1 & 2). The short-form molted every 2.5–2.8 days and the long-form molted every 2.8–3.7 days. The mean growth rate calculated from the standard length (mm d−1) of the short-form was 0.43–0.84 (Test 1 & 2), and in the long-form the values were 0.84–1.25 (Test 1 & 2). The poor cyst production of the long-form may be explained by inadequate food resources that did not fulfill the nutritional requirements for reproduction. Given its prolific uniparental reproduction (vs. biparental reproduction), the short-form Triops appears as a good potential candidate for aquaculture.
