scholarly journals Is the matamata only one species? Morphological variation and color polymorphism in the South American turtle Chelus fimbriatus (Schneider, 1783) (Pleurodira: Chelidae)

Author(s):  
Rafaella C Garbin ◽  
Ulisses Caramaschi

Background. Studies on the geographic variation of the matamata, Chelus fimbriatus, have previously demonstrated differences between carapace shape, plastral pigmentation and the ventral coloration of the neck between populations from the Amazon and Orinoco river basins, but did not discuss whether these populations should be considered different species. The aim of this study is to evaluate the taxonomic status of C. fimbriatus and to describe its intraspecific and ontogenetic variability and sexual dimorphism based on morphology and osteology. Methods. We analyzed 277 morphological characters and 138 osteological characters of the skull and shell of 82 matamatas from the four known populations (Amazon, Orinoco, Guyana and Tocantins) and performed the Population Aggregation Analysis (PAA) species delimitation test in searching for character states that are exclusive to and fixed between populations. The t Student test was also performed in order to observe sexual dimorphism. Results. Considerable overlap in character states between different populations prevents the recognition of these populations as independent species. Chelus fimbriatus has a high level of polymorphism, particularly among morphological and color pattern characters. Unlike what have been stated on previous studies, we recognise four different carapace shapes, of which the anteriorly larger oval shape is the most common one. Two coloration patterns can be found both for the plastron and the carapace that are strongly correlated with one another, but no such correlation was observed with geographic distribution. We furthermore recognise three states of neck coloration pattern. Ontogenetic variability was observed in the coloration of the carapace, plastron, and the underside of the neck, in that juveniles have a stronger pigmentation than adults. Sexual dimorphism was established for six morphometric variables of the shell and 20 variables of the skull. As expected, females are significant larger than males for all these variables, such as carapace, plastron and skull length. New osteological characters, such as the presence of a serrated medial process in the palatine and a pair of anterolateral tubercles in the basioccipital were observed. Discussion. This is the first study to confirm the presence of sexual dimorphism in C. fimbriatus using morphological and morphometric variables and to document infraspecific variation in detail. The possible presence of two subspecies has been discussed since the 19th century based on alleged geographic variation in coloration patterns. However, this hypothesis could not be confirmed in the context of this study and the matamata should therefore still be considered a single species with a wide distribution range.

2015 ◽  
Author(s):  
Rafaella C Garbin ◽  
Ulisses Caramaschi

Background. Studies on the geographic variation of the matamata, Chelus fimbriatus, have previously demonstrated differences between carapace shape, plastral pigmentation and the ventral coloration of the neck between populations from the Amazon and Orinoco river basins, but did not discuss whether these populations should be considered different species. The aim of this study is to evaluate the taxonomic status of C. fimbriatus and to describe its intraspecific and ontogenetic variability and sexual dimorphism based on morphology and osteology. Methods. We analyzed 277 morphological characters and 138 osteological characters of the skull and shell of 82 matamatas from the four known populations (Amazon, Orinoco, Guyana and Tocantins) and performed the Population Aggregation Analysis (PAA) species delimitation test in searching for character states that are exclusive to and fixed between populations. The t Student test was also performed in order to observe sexual dimorphism. Results. Considerable overlap in character states between different populations prevents the recognition of these populations as independent species. Chelus fimbriatus has a high level of polymorphism, particularly among morphological and color pattern characters. Unlike what have been stated on previous studies, we recognise four different carapace shapes, of which the anteriorly larger oval shape is the most common one. Two coloration patterns can be found both for the plastron and the carapace that are strongly correlated with one another, but no such correlation was observed with geographic distribution. We furthermore recognise three states of neck coloration pattern. Ontogenetic variability was observed in the coloration of the carapace, plastron, and the underside of the neck, in that juveniles have a stronger pigmentation than adults. Sexual dimorphism was established for six morphometric variables of the shell and 20 variables of the skull. As expected, females are significant larger than males for all these variables, such as carapace, plastron and skull length. New osteological characters, such as the presence of a serrated medial process in the palatine and a pair of anterolateral tubercles in the basioccipital were observed. Discussion. This is the first study to confirm the presence of sexual dimorphism in C. fimbriatus using morphological and morphometric variables and to document infraspecific variation in detail. The possible presence of two subspecies has been discussed since the 19th century based on alleged geographic variation in coloration patterns. However, this hypothesis could not be confirmed in the context of this study and the matamata should therefore still be considered a single species with a wide distribution range.


2021 ◽  
Vol 9 ◽  
Author(s):  
Daniel Martin ◽  
Chiara Romano

To date, the genus Amphiduros (Annelida: Hesionidae: Amphidurine) is considered as monotypic. Its single species, Amphiduros fuscescens (Marenzeller, 1875), is well characterised by lacking proboscideal papillae and emerging acicular chaetae, as well as by having three antennae, eight pairs of tentacular cirri and inflated dorsal cirri with characteristic alternating length and colour (transparent, with median orange band and white tips) in live animals. Three specimens, one male and two females, were found below boulders at 5–7 m depth in Punta Santa Anna, Blanes and Cala Maset, Sant Feliu de Guixols (Catalan Sea, NW Mediterranean, Iberian Peninsula). Our finding allowed us to describe different, unreported morphological traits and lead us to support the existence of sexual dimorphism (in terms of colouring, cirri morphology and distribution of sexual products along the body). Despite A. fuscescens having been previously reported from the Atlantic and the Mediterranean (particularly in SE French coasts), the specimens from Blanes represent the first record of the species from the Iberian Peninsula. In addition, our molecular results strongly support that Amphiduros pacificus Hartman, 1961 from California (currently synonymised with A. fuscescens) requires to be re-described and reinstalled as a valid species. In turn, our morphological observations support suggesting all other non-Mediterranean reports of A. fuscescens, including the species still under synonymy (i.e. Amphidrornus izukai Hessle, 1925 and Amphidromus setosus Hessle, 1925) as likely being a cryptic species complex whose the taxonomic status requires further assessment.


Zootaxa ◽  
2012 ◽  
Vol 3406 (1) ◽  
pp. 39 ◽  
Author(s):  
CHELSÉA B. JOHNSON ◽  
EVAN QUAH S. H. ◽  
SHAHRUL ANUAR ◽  
M. A. MUIN ◽  
PERRY L. WOOD, JR. ◽  
...  

A review of the taxonomic status of the Bent-toed Gecko Cyrtodactylus quadrivirgatus Taylor, 1962 based on a molecularphylogeny, scalation, and color pattern analyses indicate that it is composed of a single, recently expanding, widespreadpopulation with weakly supported phylogeographic substructuring with no discrete morphological differentiation betweenpopulations. However, based on sampling, significant mean differences in selected scale counts occur between some pop-ulations. The molecular phylogeny and morphological analysis strongly indicate lineage independence between a subsetof individuals from the Bukit Panchor, Penang population and their closest relative C. pantiensis Grismer, Chan, Grismer,Wood & Belabut, 2008 from southern Peninsular Malaysia. Furthermore, the analyses indicate that the individuals of thissubset are conspecific and not part of C. quadrivirgatus as previously suggested. Additionally, this subset is morphologi-cally distinct from all other Sundaland species of Cyrtodactylus, and as such is described herein as Cyrtodactylus payacola sp. nov.


Phytotaxa ◽  
2017 ◽  
Vol 297 (2) ◽  
pp. 101 ◽  
Author(s):  
SOMAYEH MONTAZEROLGHAEM ◽  
ALFONSO SUSANNA ◽  
JUAN ANTONIO CALLEJA ◽  
VALIOLLAH MOZAFFARIAN ◽  
MOHAMMAD REZA RAHIMINEJAD

A molecular phylogeny of the genus Echinops (Asteraceae, Cardueae) based on plastid and nuclear markers is presented. The study focuses on the Iranian representatives of the genus, which constitute a larger part of Echinops. The Bayesian cpDNA tree resulted in a large polytomy. However, the Bayesian ITS tree displayed a well-resolved topology more compatible with the taxonomic treatment generally accepted in Echinops. An ITS network illustrates a close relationship of haplotypes. Mapping diagnostic morphological characters onto the ITS tree revealed a high level of homoplasy among the studied taxa. Except for the life cycle, all other morphological characters evolved many times among the clades and most of them appeared to be of low taxonomical value. Based on the nucleotide polymorphism and haplotypes, the taxonomic status of some taxa was evaluated. The independent status of E. sect. Phaeochaete was confirmed by molecular analyses and morphological characters. The paraphyletic nature of E. sect. Echinops was confirmed. As for the molecular dating, our results suggest that the genus evolved in the early Miocene but the main speciation events took place in the Pliocene-Pleistocene. The biogeographic results do not support any specific ancestral area for Echinops, yet the model states that its current diversity originated in the Irano-Turanian Region and the Eastern Mediterranean region. Some taxonomic changes are suggested, in the synonymy and placement of some taxa. 


Zootaxa ◽  
2009 ◽  
Vol 2294 (1) ◽  
pp. 1-22 ◽  
Author(s):  
RAINER SONNENBERG ◽  
ECKHARD BUSCH

The phylogeny of the West African genus Archiaphyosemion was studied with mitochondrial and nuclear DNA sequences. The results of the combined dataset presented here did not support a monophyletic group. After the exclusion of the type species of the genus, A. guineense, the remaining species form a well-supported monophyletic group. Based on these molecular results and supported by morphological data, we suggest a new name for this group, Nimbapanchax, new genus. Additionally, based on a recent collection in Guinea, two new Nimbapanchax species were described. The taxon Nimbapanchax leucopterygius, new species, is described for a nothobranchiid fish formerly misidentified as Archiaphyosemion maeseni (Poll, 1941). Nimbapanchax melanopterygius, new species, is described from the Mount Nimba region in southeastern Guinea. Both new Nimbapanchax species are clearly distinguished from their congeners by the coloration pattern of adult males. The results of the DNA data support the assumption based on color pattern and morphological characters that the new described species are sister taxa. The type of Aphyosemion maeseni Poll, 1941 was reexamined and transferred to the genus Epiplatys, a decision based on diagnostic morphological characters.


2019 ◽  
Author(s):  
Kunal Arekar ◽  
S. Sathyakumar ◽  
K. Praveen Karanth

AbstractTaxonomy is replete with groups where the species identity and classification remain unresolved. One such group is the widely distributed Hanuman langur (Colobinae: Semnopithecus). For most part of the last century, Hanuman langur was considered to be a single species with multiple subspecies. Nevertheless, recent studies using an integrative taxonomy approach suggested that this taxon is a complex, with at least three species. However, these studies did not include the Himalayan population of the Hanuman langur whose taxonomic status remains unresolved. The Himalayan population of Hanuman langurs have been classified as a distinct species with multiple subspecies or have been subsumed into other species. These classification schemes are wholly based on morphological characters and which are sometimes insufficient to delimit different species. Here, we have integrated data from multiple sources viz. morphology, DNA, and ecology to resolve the taxonomy of the Himalayan langur and to understand its distribution limit. Our results with three lines of evidence corresponding to three different species concepts show that Himalayan langur is a distinct species from S. entellus of the plains. Additionally, these results did not show any support for splitting of the Himalayan langur into multiple subspecies. Our study supports the classification proposed by Hill (1939) and we recommend Semnopithecus schistaceus, Hodgson 1840 as species name for the Himalayan langur and subsume all the known subspecies into it.


Zootaxa ◽  
2019 ◽  
Vol 4688 (2) ◽  
pp. 213-231 ◽  
Author(s):  
LAIS REIA ◽  
ANA MARIA P. F. VICENSOTTO ◽  
CLAUDIO OLIVEIRA ◽  
RICARDO C. BENINE

The species Moenkhausia australis was described based on two specimens from arroyos Trementina and Chagalalina, Rio Paraguai basin, Paraguay. Its taxonomic history is complex and for many years the species was considered a synonym of Moenkhausia sanctaefilomenae. Moenkhausia australis shares a reticulated color pattern with the Moenkhausia oligolepis/M. sanctaefilomenae complex, being more similar within the species included in the complex to M. oligolepis, M. sanctaefilomenae, and M. forestii, with which it shares a prepelvic region laterally compressed, a feature also observed in Bario steindachneri. The laterally compressed prepelvic region is inferred to be putatively synapomorphic for the subgroup herein denominated as Moenkhausia oligolepis group. Our results, based on both molecular and morphological data, support the validity of Moenkhausia australis, which can be readily distinguished from the other members of the group by possessing the following combination of characters: complete lateral line, 23–27 scales in the lateral line, and five scales series above and below the lateral line. Our analysis also indicates three genetic structured populations of M. australis, from Rio Paraguai, upper Rio Paraná, and Rio Madeira basins. Since they are not diagnosable by morphological characters, we conservatively maintain these three genetic lineages as a single species. 


Zootaxa ◽  
2021 ◽  
Vol 5052 (2) ◽  
pp. 111-129
Author(s):  
PETR G. GARIBIAN ◽  
LA-ORSRI SANOAMUANG ◽  
ALEXEY A. KOTOV

It is widely accepted among the Cladocera (Crustacea) taxonomists that almost all “cosmopolitan” taxa are represented by some un-revised complexes of cryptic species. But many macro taxa of the cladocerans are still unrevised. The aim of this work is to analyze the taxonomic status of Oriental populations of the genus Bosminopsis Richard, 1895 (Anomopoda: Bosminidae) based on morphological characters. We have studied populations from India, Myanmar, Cambodia, Thailand, Laos, Vietnam, Philippines, Malaysia and Papua New Guinea and concluded that Oriental populations belong to a single species, Bosminopsis africanus (Daday, 1908), initially described from Africa. Analysis of literature data confirms that is widely distributed through whole Oriental zone. A single large mucro, or the mucro accompanied by an additional small spine in both sexes, is the main trait which differentiates B. africanus from B. zernowi Linko, 1901 distributed in more northern regions of Eurasia.  


1999 ◽  
Vol 56 (2) ◽  
pp. 161-173 ◽  
Author(s):  
C. D. Pigott ◽  
B. Francis

Nine populations of Tilia dasystyla Steven (Tiliaceae) in the Crimean mountains (Krymskiye Gory), including the type locality at Kastel Dag, were studied in the field and sampled by collection of herbarium specimens. This material was compared with specimens referred to Tilia hegonifolia Steven collected in Crimea, the Caucasus and Iran. Measurements or scores of 21 morphological characters made on the dried material were analysed by principal components analysis and logistic regression. These analyses demonstrated that the majority of trees could be correctly allocated to either Crimea or the Caucasus and Iran on the basis of the shape of their leaves and the area of their bracts. In addition there are differences of leaf and bract texture and bract colour which can be observed in fresh material. Chromosome counts showed that Crimean trees and one Caucasian tree are tetraploid (2n = 164). It is proposed that the Crimean, Caucasian and Iranian trees be treated as a single species with at least two subspecies: Tilia dasystyla Steven subsp. dasystyla from Crimea and T. dasystyla Steven subsp. caucasica (V. Engl.) Pigott from the Caucasus and Iran.


2017 ◽  
Vol 69 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Bin Peng ◽  
Yanmei Zhang ◽  
Xiaoqin Sun ◽  
Mimi Li ◽  
Jiayu Xue ◽  
...  

A survey of intron sequence amplified polymorphism (ISAP) in conjunction with sequence characterized amplified region (SCAR) was carried out to examine the genetic relationships among 14 Dioscorea polystachya cultivars and identify the most popular cultivar ?Tiegun?. Our results revealed that there is a high level of polymorphism among these cultivars. Furthermore, in this study, ISAP markers were consistent with the morphological characters of Dioscorea polystachya cultivars and previous hypotheses on the classification of these cultivars into 2 groups via leaf and tuber shapes have been confirmed. Based on morphological characters and molecular data, we show for the first time that D. doryphora might be a single species and another progenitor of these cultivars. An ISAP fragment specific to the ?Tiegun? cultivar was converted into a SCAR marker. This marker could be used to discriminate the ?Tiegun? cultivar from the other 13 cultivars. Overall, the results of our study provide the foundations for subsequent breeding programs or conservation actions.


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