The Experts below are selected from a list of 693 Experts worldwide ranked by ideXlab platform
Bettina Reichenbacher - One of the best experts on this subject based on the ideXlab platform.
-
kenyaichthyidae fam nov and kenyaichthys gen nov first record of a fossil aplocheiloid killifish teleostei cyprinodontiformes
PLOS ONE, 2015Co-Authors: Melanie Altner, Bettina ReichenbacherAbstract:The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved - and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, Meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family †Kenyaichthyidae, the new genus †Kenyaichthys and the new species †K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places †Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group), a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of †K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of †Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised.
-
†Kenyaichthyidae fam. nov. and †Kenyaichthys gen. nov. – First Record of a Fossil Aplocheiloid Killifish (Teleostei, Cyprinodontiformes)
2015Co-Authors: Melanie Altner, Bettina ReichenbacherAbstract:The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved - and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, Meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family †Kenyaichthyidae, the new genus †Kenyaichthys and the new species †K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places †Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group), a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of †K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of †Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised.
Melanie Altner - One of the best experts on this subject based on the ideXlab platform.
-
kenyaichthyidae fam nov and kenyaichthys gen nov first record of a fossil aplocheiloid killifish teleostei cyprinodontiformes
PLOS ONE, 2015Co-Authors: Melanie Altner, Bettina ReichenbacherAbstract:The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved - and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, Meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family †Kenyaichthyidae, the new genus †Kenyaichthys and the new species †K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places †Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group), a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of †K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of †Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised.
-
†Kenyaichthyidae fam. nov. and †Kenyaichthys gen. nov. – First Record of a Fossil Aplocheiloid Killifish (Teleostei, Cyprinodontiformes)
2015Co-Authors: Melanie Altner, Bettina ReichenbacherAbstract:The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved - and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, Meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family †Kenyaichthyidae, the new genus †Kenyaichthys and the new species †K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places †Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group), a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of †K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of †Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised.
Jos Snoeks - One of the best experts on this subject based on the ideXlab platform.
-
Additional file 6: of Delineating species along shifting shorelines: Tropheus (Teleostei, Cichlidae) from the southern subbasin of Lake Tanganyika
2018Co-Authors: Maarten Van Steenberge, Joost Raeymaekers, Pascal Hablützel, Maarten Vanhove, Stephan Koblmüller, Jos SnoeksAbstract:Morphological variation vs. geographical distance along the shoreline for the individual Meristics and measurements. Measurements were expressed as percentages of head (for measurements taken on the head) or standard length, raw data were shown for Meristics and for SL; the distance was taken along the shoreline (in km) starting from the northwesternmost locality. LOESS curves were calculated with a fixed smoothening parameter of 0.2. As this resulted in a straight line for ASp, 0.1 was used instead (*). (PDF 4487 kb
-
Delineating species along shifting shorelines: Tropheus (Teleostei, Cichlidae) from the southern subbasin of Lake Tanganyika
BMC, 2018Co-Authors: Maarten Van Steenberge, Pascal Hablützel, Stephan Koblmüller, Joost André Maria Raeymaekers, Maarten Pieterjan Maria Vanhove, Jos SnoeksAbstract:Abstract Background Species delineation is particularly challenging in taxa with substantial intra-specific variation. In systematic studies of fishes, Meristics and linear measurements that describe shape are often used to delineate species. Yet, little is known about the taxonomic value of these two types of morphological characteristics. Here, we used Tropheus (Teleostei, Cichlidae) from the southern subbasin of Lake Tanganyika to test which of these types of characters best matched genetic lineages that could represent species in this group of stenotypic rock-dwelling cichlids. We further investigated intra-population variation in morphology. By linking this to a proxy of a population’s age, we could assess the evolutionary stability of different kinds of morphological markers. Results Morphological data was collected from 570 specimens originating from 86 localities. An AFLP approach revealed the presence of five lineages in the southern subbasin: T. moorii, T. brichardi, T. sp. ‘maculatus’, T. sp. ‘Mpimbwe’ and T. sp. ‘red’, which we consider to represent distinct species. Although both types of morphological data supported this classification, a comparison of PST-values that describe inter-population morphological differentiation, revealed a better correspondence between the taxon delineation based on AFLP data and the patterns revealed by an analysis of Meristics than between the AFLP-based taxon delineation and the patterns revealed by an analysis of shape. However, classifying southern populations of Tropheus was inherently difficult as they contained a large amount of clinal variation, both in genetic and in morphological data, and both within and among species. A scenario is put forward to explain the current-day distribution of the species and colour varieties and the observed clinal variation across the subbasin’s shoreline. Additionally, we observed that variation in shape was larger in populations from shallow shores whereas populations from steep shores were more variable in Meristics. This difference is explained in terms of the different timescales at which small and large scale lake level fluctuations affected populations of littoral cichlids at steep and shallow shores. Conclusions Our results showed Meristics to be more evolutionary stable, and of higher taxonomic value for species delimitation in Tropheus, than linear measurements that describe shape. These results should be taken into account when interpreting morphological differences between populations of highly stenotypic species, such as littoral cichlids from the Great East African Lakes
-
PCA on Meristics of S. babaulti and S. pleurospilus.
2015Co-Authors: Maarten Van Steenberge, Antoine Pariselle, Tine Huyse, Filip A. M. Volckaert, Jos Snoeks, Maarten P. M. VanhoveAbstract:Loadings and explained variance of the first four PC of a PCA conducted on the correlation matrix of 15 Meristics taken on 60 specimens.PCA on Meristics of S. babaulti and S. pleurospilus.
-
PCA on Meristics of the inter-specific analysis.
2015Co-Authors: Maarten Van Steenberge, Antoine Pariselle, Tine Huyse, Filip A. M. Volckaert, Jos Snoeks, Maarten P. M. VanhoveAbstract:PC2 vs. PC1 of a PCA on 16 Meristics from 114 specimens belonging to the six Simochromis and Pseudosimochromis species.
-
PCA on Meristics of S. babaulti and S. pleurospilus.
2015Co-Authors: Maarten Van Steenberge, Antoine Pariselle, Tine Huyse, Filip A. M. Volckaert, Jos Snoeks, Maarten P. M. VanhoveAbstract:PC2 vs. PC1 of a PCA on the 15 Meristics for 60 specimens belonging to four geographical groups of S. babaulti and to S. pleurospilus (the southern group).
Cemal Turan - One of the best experts on this subject based on the ideXlab platform.
-
systematic status of nine mullet species mugilidae in the mediterranean sea
Turkish Journal of Fisheries and Aquatic Sciences, 2011Co-Authors: Cemal Turan, Mevlut Gurlek, Deniz Erguden, Deniz Yaglioglu, Bayram OzturkAbstract:Systematic relationships among four genera and nine species (Mugil cephalus Linnaeus, 1758, Mugil soiuy Basilewsky, 1855, Liza ramada (Risso, 1827), Liza aurata (Risso, 1810), Liza abu (Heckel, 1843), Liza saliens (Risso, 1810), Liza carinata (Valenciennes, 1836), Chelon labrosus (Risso, 1827), Oedalechilus labeo (Cuvier, 1829)) of the Mugilidae family living in the Mediterranean Sea were investigated using morphological characters. Moreover the systematic relationship of M. soiuy and L. abu among other mullet species was investigated in the present study for the first time. Hierarchical cluster analyses of morphometric data were not concordant with the meristic data. Meristic characters in the present study were more discriminative than morphometric characters in terms of taxonomic classification of the mullets. According to meristic data in UPGMA tree, all nine species were grouped in two main branching. In the first branch, C. labrosus and O. labeo were clustered as closest taxa, and being the sister group to the L. aurata. The other four Liza species produced two sub-branching in this group; L. carinata was branched with L. saliens, which is neighbour to L. ramada. In the second branch two species, M. soiuy and L. abu were clustered together and highly isolated from others. M cephalus was clustered as a most differentiated species from all other Mugil species.
-
morphologic and allozyme analyses of european anchovy engraulis encrasicolus l 1758 in the black marmara and aegean seas
Acta Adriatica, 2009Co-Authors: Zeliha Erdogan, Cemal Turan, Hatice Torcu KocAbstract:The morphologic and genetic variations of Engraulis encrasicolus (L. 1758) were studied based on morphometric, meristic and allozyme analyses. Samples were collected throughout the Black, Marmara and Aegean Seas. Discriminant function analysis of both morphometric and meristic characters indicated the existence of four morphologically differentiated groups of E. encrasicolus. The Aegean Sea and Marmara Sea samples were the most isolated from all others for morphometric and meristic characters. Genetic analyses indicated great variability but suggested low levels of differentiation in the eastern Black Sea samples. However, the low genetic distance between this and other samples suggests the existence of hybridization between the Azov and eastern Black Sea populations. Nonetheless, genetic analysis showed that these levels were significant and the population structure should be analysed using markers able to detect a greater degree of population differentiation.
-
morphometric and meristic variation between stocks of bluefish pomatomus saltatrix in the black marmara aegean and northeastern mediterranean seas
Fisheries Research, 2006Co-Authors: Cemal Turan, Bayram Ozturk, Mustafa Oral, Ertug DuzgunesAbstract:Abstract The genetic and morphological variation of Pomatomus saltatrix were studied based on morphometric and meristic analyses of samples collected throughout the Black Seas, Marmara, Aegean and eastern Mediterranean Seas. In discriminant function analysis, plotting first and second discriminant functions explained 61 and 77% of the between-group variation for morphometric and meristic analyses, respectively, and indicated existence of three morphologically differentiated groups of P. saltatrix . Consistent differences in the summer and winter samples of the eastern Black Sea, the adjacent sea populations of western Black Sea, Marmara Sea and Aegean Sea, which were overlapping and northeastern Mediterranean samples were observed. The detected pattern of morphological differentiation also reflects their geographic isolation. The overall random assignment of individuals into their original population was moderate for morphometric (54%) and meristic (64%) characters. Both for morphometric and meristic analysis, the highest reclassification rate was observed for the eastern Black Sea and northeastern Mediterranean Sea samples, the most clearly isolated groups. Examination of the contribution of each morphometric and meristic character to the first and second discriminant functions revealed that the observed differences were mainly from head measurements, body depth, lateral scale and vertebrate numbers, indicating these characters to be important in the description of population characteristics. Mantel's test showed that the Mahalanobis distance between the populations both for morphometric ( r = −0.282; P = 0.226) and meristic ( r = 0.632; P = 0.119) were not significantly associated with their geographical distances.
-
stock identification of mediterranean horse mackerel trachurus mediterraneus using morphometric and meristic characters
Ices Journal of Marine Science, 2004Co-Authors: Cemal TuranAbstract:Turan, C. 2004. Stock identification of Mediterranean horse mackerel (Trachurusmediterraneus) using morphometric and meristic characters. e ICES Journal of MarineScience, 61: 774e781.Morphologic differentiation among stocks of Mediterranean horse mackerel, Trachurusmediterraneus, throughout the Black, Marmara, Aegean and Eastern Mediterranean Seas,was investigated using morphometric and meristic characters. Discriminant functionanalysis of both morphometric and meristic characters suggested that there is restrictedmigration of mackerel among the adjacent seas. Overlapping of four Black sea samples onthe discriminant space in morphometric and meristic characters suggested that there is oneself-recruiting population in the area. The Marmara sea samples were the most isolatedsamples from all others for both morphometric and meristic characters, which may indicateexistence of a distinguishable mackerel stock in the area. The sample from the Aegean Seawas grouped with one geographically close Mediterranean sample based on morphometrics,and separated from all other Mediterranean samples based on meristic characters,suggesting some degree of intermingling between these areas. Examination of thecontribution of each morphometric variable to canonical functions indicated that differencesamong samples seemed to be associated with the anterior part of the body. In meristicanalyses, highest contributions to canonical functions were associated with the number ofgill rakers and pectoral fin rays.
Alberto G Murta - One of the best experts on this subject based on the ideXlab platform.
-
morphological variation of horse mackerel trachurus trachurus in the iberian and north african atlantic implications for stock identification
Ices Journal of Marine Science, 2000Co-Authors: Alberto G MurtaAbstract:The current delimitation of the Atlanto–Iberian stock of horse mackerel, Trachurus trachurus (Linnaeus, 1758), is based on scant biological evidence. Here, the location of the southern boundary of this stock is investigated through the analysis of several morphometric and meristic characteristics. A total of 384 horse mackerel were sampled from three areas off the Portuguese, one off the Spanish (Gulf of Cadiz) and another off the Moroccan coast, and compared using multivariate techniques. Some 14 morphometric and five meristic characters were analysed using hierarchical cluster analysis, multivariate discriminant analysis and randomization tests. Morphometric characteristics showed considerably greater discriminatory power to distinguish individuals from different areas than did the meristic characters. All morphometrical analyses showed similar results: the greatest differences were found between the Gulf of Cadiz and all other groups, while fish from the Portuguese coast appeared more similar to each other than to those from Moroccan waters. Meristic characters did not allow a clear distinction between geographical areas, with the Mahalanobis distances among areas being an order of magnitude smaller than those for the analysis of the morphometrics. If these results are corroborated by further biological evidence (such as genetical or parasitological data), there is a strong argument for the southern limit of the Atlanto–Iberian stock of horse mackerel to be revised. 2000 International Council for the Exploration of the Sea