Pub Date : 2019-06-26DOI: 10.1163/18759866-20191403
Miguel A. Meca, P. Drake, Daniel Martin
The polychaete Oxydromus okupa lives in association with the bivalves Scrobicularia plana and Macomopsis pellucida in the intertidal of Río San Pedro (CI = Cádiz Intertidal) and adjacent to CHipiona (CH) harbour, and in the subtidal of the Bay of Cádiz (CS = Cádiz Subtidal). We analyse these populations morphometrically, ecologically (including infestation characteristics) and genetically (intertidal populations, 16S and ITS-1 genes). We consider “host”, “environment” and the combined “host and environment” as possible factors of interpopulation variability. Morphometry revealed three well-defined clusters for CI, CH and CS, showing intergroup phenotypic differences ranging from 35 to 50%. Hosts shell lengths ranged between 26 and 36 mm for S. plana and 20 and 28 mm for M. pellucida. The infestation of small M. pellucida by juvenile O. okupa suggests they show an active size segregation behaviour. The intertidal seems to be less favourable (infestation rate <25% vs. up to 65% in the subtidal), and did not show recent bottleneck events. Overall, CI and CH were genetically homogeneous, but showed a significant divergence (one dominant haplotype in each host species), suggesting host shift as being a soft barrier to gene flow. Most characters related with host-entering varied among populations, suggesting symbiotic behaviour to play a key role in reducing panmixia and leading to the initial phases of a speciation process in sympatric symbiotic populations. Polyxeny and symbiotic behaviour in O. okupa seem thus to be underlying mechanisms contributing to its great phenotypic variety, marked ecological differences, and genetic divergence.
{"title":"Does polyxenous symbiosis promote sympatric divergence? A morphometric and phylogeographic approach based on Oxydromus okupa (Annelida, Polychaeta, Hesionidae)","authors":"Miguel A. Meca, P. Drake, Daniel Martin","doi":"10.1163/18759866-20191403","DOIUrl":"https://doi.org/10.1163/18759866-20191403","url":null,"abstract":"The polychaete Oxydromus okupa lives in association with the bivalves Scrobicularia plana and Macomopsis pellucida in the intertidal of Río San Pedro (CI = Cádiz Intertidal) and adjacent to CHipiona (CH) harbour, and in the subtidal of the Bay of Cádiz (CS = Cádiz Subtidal). We analyse these populations morphometrically, ecologically (including infestation characteristics) and genetically (intertidal populations, 16S and ITS-1 genes). We consider “host”, “environment” and the combined “host and environment” as possible factors of interpopulation variability. Morphometry revealed three well-defined clusters for CI, CH and CS, showing intergroup phenotypic differences ranging from 35 to 50%. Hosts shell lengths ranged between 26 and 36 mm for S. plana and 20 and 28 mm for M. pellucida. The infestation of small M. pellucida by juvenile O. okupa suggests they show an active size segregation behaviour. The intertidal seems to be less favourable (infestation rate <25% vs. up to 65% in the subtidal), and did not show recent bottleneck events. Overall, CI and CH were genetically homogeneous, but showed a significant divergence (one dominant haplotype in each host species), suggesting host shift as being a soft barrier to gene flow. Most characters related with host-entering varied among populations, suggesting symbiotic behaviour to play a key role in reducing panmixia and leading to the initial phases of a speciation process in sympatric symbiotic populations. Polyxeny and symbiotic behaviour in O. okupa seem thus to be underlying mechanisms contributing to its great phenotypic variety, marked ecological differences, and genetic divergence.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191403","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46266777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-14DOI: 10.1163/18759866-20191357
Cessa Rauch, B. Hoeksema, B. Hermanto, C. Fransen
Most marine palaemonid shrimp species live in symbiosis with invertebrates of various phyla. These associations range from weak epibiosis to obligatory endosymbiosis and from restricted commensalism to semi-parasitism. On coral reefs, such symbiotic shrimps can contribute to the associated biodiversity of reef corals. Among the host taxa, mushroom corals (Cnidaria: Anthozoa: Fungiidae) are known to harbour various groups of symbionts, including shrimps. Some but not all of these associated species are host-specific. Because data on the host specificity of shrimps on mushroom corals are scarce, shrimp species of the genus Periclimenes were collected from mushroom corals during fieldwork in Lembeh Strait, North Sulawesi, Indonesia. Using molecular (COI barcoding gene) and morphological methods, three species of Periclimenes were identified: P. diversipes, P. watamuae and a species new to science, P. subcorallum sp. nov., described herein. Their host specificity was variable, with eight, three and two fungiid host records, respectively. It is concluded that shrimp species of the genus Periclimenes show much overlap in their host choice and that particular morphological traits in the host species appear to play a more important role than phylogenetic affinities within the host group.
大多数海洋古虾与各种门的无脊椎动物共生。这些关联范围从弱的附生到强制性的内共生，从有限的共生到半寄生。在珊瑚礁上，这种共生虾可以为珊瑚礁珊瑚的生物多样性做出贡献。在宿主分类群中，蘑菇珊瑚(刺胞纲:珊瑚虫纲:真菌科)被认为是各种共生体的避难所，包括虾。这些相关物种中的一些(但不是全部)是宿主特异性的。由于对虾在蘑菇珊瑚上寄主特异性的资料较少，在印度尼西亚北苏拉威西岛Lembeh海峡的实地调查中，从蘑菇珊瑚中采集了Periclimenes属虾种。利用分子(COI条形码基因)和形态学方法鉴定了3个种:P. diversity, P. watamuae和一个科学新种P. subcorallum sp. nov.。它们的宿主特异性是可变的，分别有8个、3个和2个真菌宿主记录。综上所述，周缘虾属虾种在寄主选择上有很大的重叠，寄主物种的特定形态特征似乎比寄主群体内的系统发育亲缘关系起更重要的作用。
{"title":"Shrimps of the genus Periclimenes (Crustacea, Decapoda, Palaemonidae) associated with mushroom corals (Scleractinia, Fungiidae): linking DNA barcodes to morphology","authors":"Cessa Rauch, B. Hoeksema, B. Hermanto, C. Fransen","doi":"10.1163/18759866-20191357","DOIUrl":"https://doi.org/10.1163/18759866-20191357","url":null,"abstract":"Most marine palaemonid shrimp species live in symbiosis with invertebrates of various phyla. These associations range from weak epibiosis to obligatory endosymbiosis and from restricted commensalism to semi-parasitism. On coral reefs, such symbiotic shrimps can contribute to the associated biodiversity of reef corals. Among the host taxa, mushroom corals (Cnidaria: Anthozoa: Fungiidae) are known to harbour various groups of symbionts, including shrimps. Some but not all of these associated species are host-specific. Because data on the host specificity of shrimps on mushroom corals are scarce, shrimp species of the genus Periclimenes were collected from mushroom corals during fieldwork in Lembeh Strait, North Sulawesi, Indonesia. Using molecular (COI barcoding gene) and morphological methods, three species of Periclimenes were identified: P. diversipes, P. watamuae and a species new to science, P. subcorallum sp. nov., described herein. Their host specificity was variable, with eight, three and two fungiid host records, respectively. It is concluded that shrimp species of the genus Periclimenes show much overlap in their host choice and that particular morphological traits in the host species appear to play a more important role than phylogenetic affinities within the host group.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191357","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42430061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-30DOI: 10.1163/18759866-20191406
G. Stocchino, R. Sluys, A. Harrath, L. Mansour, R. Manconi
Invasions of alien species form one of the major threats to global biodiversity. Among planarian flatworms many species are known to be invasive, in several cases strongly affecting local ecosystems. Therefore, a detailed knowledge on the biology of an invasive species is of utmost importance for understanding the process of invasion, the cause of its success, and the subsequent ecological impact on native species. This paper provides new information on the biology of introduced populations of the freshwater flatworm Girardia tigrina (Girard, 1850) from Europe. This species is a native of the Nearctic Region that was accidentally introduced into Europe in the 1920s. Since then, numerous records across the European continent bear witness of the invasiveness of this species, although only a few studies focused on the biology of the introduced populations. We report on the morphology of sexualized individuals from a fissiparous Italian population, representing the second record of spontaneous sexualization of fissiparous individuals in this species. A detailed morphological account of the reproductive apparatus of these ex-fissiparous animals is presented. Our results increased the number of morphological groups previously recognized for European populations of G. tigrina, thus corroborating the hypothesis on multiple independent introductions to this continent. Karyological results obtained from our fissiparous Italian individuals revealed a constant diploid chromosome complement of sixteen chromosomes. Further, we document the marked intraspecific variation in several morphological features of this species.
{"title":"The invasive alien freshwater flatworm Girardia tigrina (Girard, 1850) (Platyhelminthes, Tricladida) in Western Europe: new insights into its morphology, karyology and reproductive biology","authors":"G. Stocchino, R. Sluys, A. Harrath, L. Mansour, R. Manconi","doi":"10.1163/18759866-20191406","DOIUrl":"https://doi.org/10.1163/18759866-20191406","url":null,"abstract":"Invasions of alien species form one of the major threats to global biodiversity. Among planarian flatworms many species are known to be invasive, in several cases strongly affecting local ecosystems. Therefore, a detailed knowledge on the biology of an invasive species is of utmost importance for understanding the process of invasion, the cause of its success, and the subsequent ecological impact on native species. This paper provides new information on the biology of introduced populations of the freshwater flatworm Girardia tigrina (Girard, 1850) from Europe. This species is a native of the Nearctic Region that was accidentally introduced into Europe in the 1920s. Since then, numerous records across the European continent bear witness of the invasiveness of this species, although only a few studies focused on the biology of the introduced populations. We report on the morphology of sexualized individuals from a fissiparous Italian population, representing the second record of spontaneous sexualization of fissiparous individuals in this species. A detailed morphological account of the reproductive apparatus of these ex-fissiparous animals is presented. Our results increased the number of morphological groups previously recognized for European populations of G. tigrina, thus corroborating the hypothesis on multiple independent introductions to this continent. Karyological results obtained from our fissiparous Italian individuals revealed a constant diploid chromosome complement of sixteen chromosomes. Further, we document the marked intraspecific variation in several morphological features of this species.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191406","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41744112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-15DOI: 10.1163/18759866-20191344
Gerrit Potkamp, C. Fransen
Over the last century, a large body of literature emerged on mechanisms driving speciation. Most of the research into these questions focussed on terrestrial systems, while research in marine systems lagged behind. Here, we review the population genetic mechanisms and geographic context of 33 potential cases of speciation with gene flow in the marine realm, using six criteria inferred from theoretical models of speciation. Speciation with gene flow occurs in a wide range of marine taxa. Single traits, which induce assortative mating and are subjected to disruptive selection, such as differences in host-associations in invertebrates or colour pattern in tropical fish, are potentially responsible for a decrease in gene flow and may be driving divergence in the majority of cases. However, much remains unknown, and with the current knowledge, the frequency of ecological speciation with gene flow in marine systems remains difficult to estimate. Standardized, generally applicable statistical methods, explicitly testing different hypotheses of speciation, are, going forward, required to confidently infer speciation with gene flow.
{"title":"Speciation with gene flow in marine systems","authors":"Gerrit Potkamp, C. Fransen","doi":"10.1163/18759866-20191344","DOIUrl":"https://doi.org/10.1163/18759866-20191344","url":null,"abstract":"Over the last century, a large body of literature emerged on mechanisms driving speciation. Most of the research into these questions focussed on terrestrial systems, while research in marine systems lagged behind. Here, we review the population genetic mechanisms and geographic context of 33 potential cases of speciation with gene flow in the marine realm, using six criteria inferred from theoretical models of speciation. Speciation with gene flow occurs in a wide range of marine taxa. Single traits, which induce assortative mating and are subjected to disruptive selection, such as differences in host-associations in invertebrates or colour pattern in tropical fish, are potentially responsible for a decrease in gene flow and may be driving divergence in the majority of cases. However, much remains unknown, and with the current knowledge, the frequency of ecological speciation with gene flow in marine systems remains difficult to estimate. Standardized, generally applicable statistical methods, explicitly testing different hypotheses of speciation, are, going forward, required to confidently infer speciation with gene flow.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191344","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48685787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-11DOI: 10.1163/18759866-20191345
A. Archidona‐Yuste, C. Cantalapiedra‐Navarrete, P. Castillo, J. E. Palomares-Rius
The genus Longidorus constitutes a large group of approximately 170 species of plant-ectoparasitic nematodes that are polyphagous and distributed almost worldwide. Some of the species of this genus are vectors of plant viruses. Species discrimination in Longidorus is difficult because the morphology is very conservative, and morphometric characters often overlap, leading to potential misidentification. Integrative taxonomy, based on the combination of molecular analyses with morphology, is a useful and necessary approach in Longidorus species identification. In Spain from 2014 to 2017, we conducted nematode surveys among cultivated and wild plants, from which we identified 13 populations of Longidorus, two of which appeared to represent new species and are described herein as L. iliturgiensis sp. nov. and L. pacensis sp. nov., and 11 populations belonging to eight known species: L. africanus, L. baeticus, L. carpetanensis, L. fasciatus, L. nevesi, L. cf. olegi, L. pini, and L. vallensis. Three species are new geographical records for Spain (L. nevesi, L. cf. olegi, and L. africanus). We report molecular data for L. nevesi, L. cf. olegi, L. carpetanensis and L. pini for the first time. Additionally, we describe the males of L. pini and the juveniles of L. cf. olegi.
{"title":"Molecular phylogenetic analysis and comparative morphology reveals the diversity and distribution of needle nematodes of the genus Longidorus (Dorylaimida: Longidoridae) from Spain","authors":"A. Archidona‐Yuste, C. Cantalapiedra‐Navarrete, P. Castillo, J. E. Palomares-Rius","doi":"10.1163/18759866-20191345","DOIUrl":"https://doi.org/10.1163/18759866-20191345","url":null,"abstract":"The genus Longidorus constitutes a large group of approximately 170 species of plant-ectoparasitic nematodes that are polyphagous and distributed almost worldwide. Some of the species of this genus are vectors of plant viruses. Species discrimination in Longidorus is difficult because the morphology is very conservative, and morphometric characters often overlap, leading to potential misidentification. Integrative taxonomy, based on the combination of molecular analyses with morphology, is a useful and necessary approach in Longidorus species identification. In Spain from 2014 to 2017, we conducted nematode surveys among cultivated and wild plants, from which we identified 13 populations of Longidorus, two of which appeared to represent new species and are described herein as L. iliturgiensis sp. nov. and L. pacensis sp. nov., and 11 populations belonging to eight known species: L. africanus, L. baeticus, L. carpetanensis, L. fasciatus, L. nevesi, L. cf. olegi, L. pini, and L. vallensis. Three species are new geographical records for Spain (L. nevesi, L. cf. olegi, and L. africanus). We report molecular data for L. nevesi, L. cf. olegi, \u0000L. carpetanensis and L. pini for the first time. Additionally, we describe the males of L. pini and the juveniles of L. cf. olegi.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191345","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45563781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-11DOI: 10.1163/18759866-20191347
B. Huber, A. Chao
Ratio-like approaches for estimating global species richness have been criticised for their unjustified extrapolation from regional to global patterns. Here we explore the use of cumulative percentages of ‘new’ (i.e., not formally described) species over large geographic areas (‘megatransects’) as a means to overcome this problem. In addition, we take into account undetected species and illustrate these combined methods by applying them to a family of spiders (Pholcidae) that currently contains some 1,700 described species. The raw global cumulative percentage of new species (‘new’ as of the end of 2008, when 1,001 species were formally described) is 75.1%, and is relatively constant across large biogeographic regions. Undetected species are estimated using the Chao2 estimator based on species incidence data (date by species and locality by species matrices). The estimated percentage of new species based on the date by species matrices is 76.0% with an estimated standard error (s.e.) of 2.6%. This leads to an estimated global species richness of about 4,200 with a 95% confidence interval of (3,300, 5,000). The corresponding values based on locality by species matrices are 84.2% (s.e. 3.0%) and 6,300 with a 95% confidence interval of (4,000, 8,600). Our results suggest that the currently known 1,700 species of Pholcidae may represent no more than about 25–40% of the total species richness. The impact of further biasing factors like geography, species size and distribution, cryptic species, and model assumptions needs to be explored.
{"title":"Inferring global species richness from megatransect data and undetected species estimates","authors":"B. Huber, A. Chao","doi":"10.1163/18759866-20191347","DOIUrl":"https://doi.org/10.1163/18759866-20191347","url":null,"abstract":"Ratio-like approaches for estimating global species richness have been criticised for their unjustified extrapolation from regional to global patterns. Here we explore the use of cumulative percentages of ‘new’ (i.e., not formally described) species over large geographic areas (‘megatransects’) as a means to overcome this problem. In addition, we take into account undetected species and illustrate these combined methods by applying them to a family of spiders (Pholcidae) that currently contains some 1,700 described species. The raw global cumulative percentage of new species (‘new’ as of the end of 2008, when 1,001 species were formally described) is 75.1%, and is relatively constant across large biogeographic regions. Undetected species are estimated using the Chao2 estimator based on species incidence data (date by species and locality by species matrices). The estimated percentage of new species based on the date by species matrices is 76.0% with an estimated standard error (s.e.) of 2.6%. This leads to an estimated global species richness of about 4,200 with a 95% confidence interval of (3,300, 5,000). The corresponding values based on locality by species matrices are 84.2% (s.e. 3.0%) and 6,300 with a 95% confidence interval of (4,000, 8,600). Our results suggest that the currently known 1,700 species of Pholcidae may represent no more than about 25–40% of the total species richness. The impact of further biasing factors like geography, species size and distribution, cryptic species, and model assumptions needs to be explored.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191347","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44661890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-11DOI: 10.1163/18759866-20191350
P. Gąsiorek, D. Stec, Witold Morek, Ł. Michalczyk
Isohypsibioidea are most likely the most basally branching evolutionary lineage of eutardigrades. Despite being second largest eutardigrade order, phylogenetic relationships and systematics within this group remain largely unresolved. Broad taxon sampling, especially within one of the most speciose tardigrade genera, Isohypsibius Thulin, 1928, and application of both comparative morphological methods (light contrast and scanning electron microscopy imaging of external morphology and buccal apparatuses) and phylogenetic framework (18S + 28S rRNA sequences) resulted in the most comprehensive study devoted to this order so far. Two new families are erected from the currently recognised family Isohypsibiidae: Doryphoribiidae fam. nov., comprising all aquatic isohypsibioids and some terrestrial isohypsibioid taxa equipped with the ventral lamina; and Halobiotidae fam. nov., secondarily marine eutardigrades with unique adaptations to sea environment. We also split Isohypsibius into four genera to accommodate phylogenetic, morphological and ecological variation within the genus: terrestrial Isohypsibius s.s. (Isohypsibiidae), with smooth or sculptured cuticle but without gibbosities; terrestrial Dianea gen. nov. (Isohypsibiidae), with small and pointy gibbosities; terrestrial Ursulinius gen. nov. (Isohypsibiidae), with large and rounded gibbosities; and aquatic Grevenius gen. nov. (Doryphoribiidae fam. nov.), typically with rough cuticle and claws with branches of very similar heigths. Claw morphology is reviewed and, for the first time, shown to encompass a number of morphotypes that correlate with clades recovered in the molecular analysis. The anatomy of pharynx and cuticle are also shown to be of high value in distinguishing supraspecific taxa in Isohypsibioidea. Taxonomy of all isohypsibioid families and genera is discussed, with special emphasis on the newly erected entities. Finally, a dychotomous diagnostic key to all currently recognised isohypsibioid families and genera is provided.
{"title":"Deceptive conservatism of claws: distinct phyletic lineages concealed within Isohypsibioidea (Eutardigrada) revealed by molecular and morphological evidence","authors":"P. Gąsiorek, D. Stec, Witold Morek, Ł. Michalczyk","doi":"10.1163/18759866-20191350","DOIUrl":"https://doi.org/10.1163/18759866-20191350","url":null,"abstract":"Isohypsibioidea are most likely the most basally branching evolutionary lineage of eutardigrades. Despite being second largest eutardigrade order, phylogenetic relationships and systematics within this group remain largely unresolved. Broad taxon sampling, especially within one of the most speciose tardigrade genera, Isohypsibius\u0000Thulin, 1928, and application of both comparative morphological methods (light contrast and scanning electron microscopy imaging of external morphology and buccal apparatuses) and phylogenetic framework (18S + 28S rRNA sequences) resulted in the most comprehensive study devoted to this order so far. Two new families are erected from the currently recognised family Isohypsibiidae: Doryphoribiidae fam. nov., comprising all aquatic isohypsibioids and some terrestrial isohypsibioid taxa equipped with the ventral lamina; and Halobiotidae fam. nov., secondarily marine eutardigrades with unique adaptations to sea environment. We also split Isohypsibius into four genera to accommodate phylogenetic, morphological and ecological variation within the genus: terrestrial Isohypsibius s.s. (Isohypsibiidae), with smooth or sculptured cuticle but without gibbosities; terrestrial Dianea gen. nov. (Isohypsibiidae), with small and pointy gibbosities; terrestrial Ursulinius gen. nov. (Isohypsibiidae), with large and rounded gibbosities; and aquatic Grevenius gen. nov. (Doryphoribiidae fam. nov.), typically with rough cuticle and claws with branches of very similar heigths. Claw morphology is reviewed and, for the first time, shown to encompass a number of morphotypes that correlate with clades recovered in the molecular analysis. The anatomy of pharynx and cuticle are also shown to be of high value in distinguishing supraspecific taxa in Isohypsibioidea. Taxonomy of all isohypsibioid families and genera is discussed, with special emphasis on the newly erected entities. Finally, a dychotomous diagnostic key to all currently recognised isohypsibioid families and genera is provided.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191350","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46791977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-11DOI: 10.1163/18759866-20191355
Y. W. Lau, F. Stokvis, Yukimitsu Imahara, J. Reimer
Stoloniferan octocorals (Cnidaria: Anthozoa: Octocorallia: Alcyonacea) are a relatively unexplored fauna in the Ryukyus (southern Japan), known to be a tropical marine region of high biodiversity and endemism of species. Specimens of stoloniferous octocorals were collected during fieldwork along the coasts of two islands (Okinawa and Iriomote) in the Okinawa Prefecture. Despite their phenotypic polyp variation, this study shows their morphological and molecular uniqueness, leading to the description of a new genus with a single species: Hanabira yukibana, gen. nov., sp. nov. They are placed within the Clavulariidae and form a sister clade basally to the genus Knopia Alderslade & McFadden, 2007 and species of Clavularia Blainville, 1830. The polyps of this new species show morphological variation in both shape and sclerite density, but there is conformity in the typical overall petal shaped tentacles, which have fused pinnules (pseudopinnules). Depending on the densities of their sclerites and their photosynthetic endosymbiotic algae (zooxanthellae) of the family Symbiodiniaceae, there is a characteristic sheen present in the tentacles. Moreover, the zooxanthellae hosted by our specimens form a clear, small-scale biogeographic pattern; all H. yukibana specimens from Okinawa Island contained zooxanthellae of the genus Cladocopium Lajeunesse & H.J. Jeong, 2018 (= former Symbiodinium ‘Clade C’) and all specimens from Iriomote Island hosted zooxanthellae of the genus Durusdinium LaJeunesse, 2018 (= former Symbiodinium ‘Clade D’). These results show the potential for variation among the Symbiodiniaceae floras within octocorals, something that has not yet been investigated for the large majority of zooxanthellate octocoral species.
八栖珊瑚(刺胞目:珊瑚虫目:八栖珊瑚目:Alcyonacea)是琉球(日本南部)一个相对未被开发的动物群，已知是一个具有高度生物多样性和特有物种的热带海洋地区。在冲绳县两个岛(冲绳岛和伊洛摩岛)海岸的野外调查中采集了匍匐茎的八爪珊瑚标本。尽管它们在表型上存在差异，但本研究显示了它们在形态和分子上的独特性，导致了一个新属的描述:Hanabira yukibana, gen. nov.， p. nov.。它们被放置在Clavulariidae中，并与KnopiaAlderslade & McFadden, 2007和Clavularia Blainville, 1830形成了一个姐妹分支。该新种的珊瑚虫在形态和硬膜密度上均有差异，但在典型的整体花瓣状触须上具有融合小叶(假小叶)的一致性。根据它们的硬膜和共生科的光合内共生藻类(虫黄藻)的密度，它们的触手上有一种特有的光泽。此外，我们的标本所寄主的虫黄藻形成了一个清晰的小尺度生物地理格局;来自冲绳岛的所有yukibana标本均含有Cladocopium Lajeunesse和H. j . Jeong, 2018(=前共生菌纲' Clade C ')，来自Iriomote岛的所有标本均含有Durusdinium Lajeunesse, 2018(=前共生菌纲' Clade D ')。这些结果表明，共生科植物群在八珊瑚中存在潜在的变异，这一点尚未对绝大多数虫黄藻类八珊瑚物种进行调查。
{"title":"The stoloniferous octocoral, Hanabira yukibana, gen. nov., sp. nov., of the southern Ryukyus has morphological and symbiont variation","authors":"Y. W. Lau, F. Stokvis, Yukimitsu Imahara, J. Reimer","doi":"10.1163/18759866-20191355","DOIUrl":"https://doi.org/10.1163/18759866-20191355","url":null,"abstract":"Stoloniferan octocorals (Cnidaria: Anthozoa: Octocorallia: Alcyonacea) are a relatively unexplored fauna in the Ryukyus (southern Japan), known to be a tropical marine region of high biodiversity and endemism of species. Specimens of stoloniferous octocorals were collected during fieldwork along the coasts of two islands (Okinawa and Iriomote) in the Okinawa Prefecture. Despite their phenotypic polyp variation, this study shows their morphological and molecular uniqueness, leading to the description of a new genus with a single species: Hanabira yukibana, gen. nov., sp. nov. They are placed within the Clavulariidae and form a sister clade basally to the genus Knopia\u0000Alderslade & McFadden, 2007 and species of Clavularia Blainville, 1830. The polyps of this new species show morphological variation in both shape and sclerite density, but there is conformity in the typical overall petal shaped tentacles, which have fused pinnules (pseudopinnules). Depending on the densities of their sclerites and their photosynthetic endosymbiotic algae (zooxanthellae) of the family Symbiodiniaceae, there is a characteristic sheen present in the tentacles. Moreover, the zooxanthellae hosted by our specimens form a clear, small-scale biogeographic pattern; all H. yukibana specimens from Okinawa Island contained zooxanthellae of the genus Cladocopium Lajeunesse & H.J. Jeong, 2018 (= former Symbiodinium ‘Clade C’) and all specimens from Iriomote Island hosted zooxanthellae of the genus Durusdinium LaJeunesse, 2018 (= former Symbiodinium ‘Clade D’). These results show the potential for variation among the Symbiodiniaceae floras within octocorals, something that has not yet been investigated for the large majority of zooxanthellate octocoral species.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-20191355","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45154315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-07DOI: 10.1163/18759866-08704005
N. Cumberlidge, S. Daniels
Surveys of the freshwater crabs of two islands in the Gulf of Guinea, Central Africa, allowed a revision of the taxonomy of two little-known island endemic species, based for the first time on adult males: Potamonautes margaritarius (A. Milne-Edwards, 1869) from São Tomé, and of P. principe Cumberlidge, Clark and Baillie, 2002, from Príncipe (Brachyura; Potamonautidae). A new species of Potamonautes from southern São Tomé (Potamonautes saotome sp. nov.) is also described that is genetically distinct and has a clearly separate geographic distribution from P. margaritarius from northern São Tomé. The new species from southern São Tomé can be recognized by a suite of characters of the carapace, thoracic sternum, and gonopods. The taxonomy of P. margaritarius (A. Milne-Edwards, 1869) is stabilized by selecting a neotype from northern São Tomé. Potamonautes principe from Príncipe is the most distinct of the three taxa, with a more swollen carapace that has smooth anterolateral margins, and a shorter, straighter male first gonopod. All three taxa are morphologically distinct species that have also been clearly distinguished as evolutionarily separate lineages by mtDNA analysis and haplotyping in an earlier study. Previous phylogenetic evidence supports two separate island colonization events at different times in the past from different ancestral populations, one to São Tomé and another to Príncipe that resulted in the establishment of the endemic freshwater crab faunas of these two islands.
对中非几内亚湾两个岛屿淡水蟹的调查，使两个鲜为人知的岛屿特有物种的分类得以修订，首次以成年雄性为基础:来自 o tom的Potamonautes margaritarius (a . Milne-Edwards, 1869年)和p.p principe Cumberlidge, Clark和Baillie, 2002年，来自Príncipe (Brachyura;Potamonautidae)。本文还报道了一种来自 o tom南地区的新种Potamonautes (Potamonautes saoome sp. nov.)，它与来自 o tom北地区的P. margaritarius具有明显的遗传差异和地理分布。该新种来自南部的东岛，可以通过甲壳、胸骨和性腺的一系列特征来识别。通过从 o tom北部选择一个新种，稳定了P. margaritarius (a . Milne-Edwards, 1869)的分类。来自Príncipe的Potamonautes principe是三个分类群中最明显的，有一个更肿胀的甲壳，有光滑的前外侧边缘，和一个更短、更直的雄性第一性腺。这三个类群在形态上是不同的物种，在早期的研究中，通过mtDNA分析和单倍型分析，它们也被清楚地区分为进化上不同的谱系。先前的系统发育证据支持在过去不同时间发生的两次独立的岛屿殖民事件，一次是来自不同祖先的种群，一次是到 o tom岛，另一次是到Príncipe岛，这导致了这两个岛屿特有的淡水蟹群的建立。
{"title":"A new species of Potamonautes from São Tomé Island, Central Africa, with redescriptions of P. margaritarius (A. Milne-Edwards, 1869) from São Tomé, and P. principe Cumberlidge, Clark and Baillie, 2002, from Príncipe (Decapoda: Potamonautidae)","authors":"N. Cumberlidge, S. Daniels","doi":"10.1163/18759866-08704005","DOIUrl":"https://doi.org/10.1163/18759866-08704005","url":null,"abstract":"Surveys of the freshwater crabs of two islands in the Gulf of Guinea, Central Africa, allowed a revision of the taxonomy of two little-known island endemic species, based for the first time on adult males: Potamonautes margaritarius (A. Milne-Edwards, 1869) from São Tomé, and of P. principe Cumberlidge, Clark and Baillie, 2002, from Príncipe (Brachyura; Potamonautidae). A new species of Potamonautes from southern São Tomé (Potamonautes saotome sp. nov.) is also described that is genetically distinct and has a clearly separate geographic distribution from P. margaritarius from northern São Tomé. The new species from southern São Tomé can be recognized by a suite of characters of the carapace, thoracic sternum, and gonopods. The taxonomy of P. margaritarius (A. Milne-Edwards, 1869) is stabilized by selecting a neotype from northern São Tomé. Potamonautes principe from Príncipe is the most distinct of the three taxa, with a more swollen carapace that has smooth anterolateral margins, and a shorter, straighter male first gonopod. All three taxa are morphologically distinct species that have also been clearly distinguished as evolutionarily separate lineages by mtDNA analysis and haplotyping in an earlier study. Previous phylogenetic evidence supports two separate island colonization events at different times in the past from different ancestral populations, one to São Tomé and another to Príncipe that resulted in the establishment of the endemic freshwater crab faunas of these two islands.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-08704005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48468959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-30DOI: 10.1163/18759866-08704004
A. Sánchez-Chardi, Marián García-Pando, E. Pujol-Buxó, M. Sans-Fuentes, M. J. López-Fuster, F. Muñoz-Muñoz
Island populations of terrestrial mammals often undergo extensive behavioural and morphological changes when separated from mainland populations. Within small mammals these changes have been mainly reported in rodents but were poorly assessed in soricomorphs. In this study we compared mandible morphology and body condition between mainland and island populations of the greater white-toothed shrew, Crocidura russula. The results indicated that island specimens were bigger and heavier than the mainland counterpart, and they showed changes in mandible shape that were associated with higher mechanical potentials. We suggest that these changes might be the result of the interaction of two main factors taking place in the island population: ecological release (i.e. the decrease of predation and interspecific competition), and consequently the increase of intraspecific competition. While the increase in size and body condition in island shrews could be a direct result from reduced predation and interspecific competition, the changes in mandible shape and the increase of both mechanical potential and sexual dimorphism could have arisen indirectly as a response to stronger intraspecific competition.
{"title":"Insularity induces changes on body and mandible morphology in a Mediterranean population of the greater white-toothed shrew Crocidura russula (Hermann, 1780)","authors":"A. Sánchez-Chardi, Marián García-Pando, E. Pujol-Buxó, M. Sans-Fuentes, M. J. López-Fuster, F. Muñoz-Muñoz","doi":"10.1163/18759866-08704004","DOIUrl":"https://doi.org/10.1163/18759866-08704004","url":null,"abstract":"Island populations of terrestrial mammals often undergo extensive behavioural and morphological changes when separated from mainland populations. Within small mammals these changes have been mainly reported in rodents but were poorly assessed in soricomorphs. In this study we compared mandible morphology and body condition between mainland and island populations of the greater white-toothed shrew, Crocidura russula. The results indicated that island specimens were bigger and heavier than the mainland counterpart, and they showed changes in mandible shape that were associated with higher mechanical potentials. We suggest that these changes might be the result of the interaction of two main factors taking place in the island population: ecological release (i.e. the decrease of predation and interspecific competition), and consequently the increase of intraspecific competition. While the increase in size and body condition in island shrews could be a direct result from reduced predation and interspecific competition, the changes in mandible shape and the increase of both mechanical potential and sexual dimorphism could have arisen indirectly as a response to stronger intraspecific competition.","PeriodicalId":55210,"journal":{"name":"Contributions to Zoology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/18759866-08704004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44157870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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