scholarly journals Assessing population-level morphometric variation of the Mountain Mullet Agonostomus monticola (Teleostei: Mugilidae) across its Middle American distribution

2017 ◽  
Vol 15 (4) ◽  
Author(s):  
Bertha P. Díaz-Murillo ◽  
Gorgonio Ruiz-Campos ◽  
Kyle R. Piller ◽  
Caleb D. McMahan ◽  
Francisco J. García-De-León ◽  
...  

ABSTRACT Population-level morphometric variation of the Mountain Mullet (Agonostomus monticola) was assessed in 419 adult specimens from 25 sample sites (river basins) across its Middle American distribution (Pacific and Atlantic-Caribbean drainages). This analysis was based on 36 standardized linear measurements and 19 landmarks on geometric morphometrics approach. Discriminant function analysis (DFA) revealed 19 linear morphological characters with significant variation among groups. Geometrically, the most notable changes were associated to the curvature of the frontal region of the head, the anterior and posterior insertion of the first dorsal and anal fins. The resulting grouping based on the DFA and geometric morphometrics techniques (Pacific-A, Pacific-B and NE México-Caribbean) were similar to those previously recovered by genetic techniques, where the Pacific-B (Ayuquila river basin) was the most different group. Our results provide morphological evidence for considering Agonostomus monticola as a complex of evolutionary entities, represented by two forms in the Pacific Ocean and another in the Atlantic Ocean.

Zootaxa ◽  
2018 ◽  
Vol 4527 (1) ◽  
pp. 75
Author(s):  
LUCIANA MARTINS

The genus Thyonella currently comprises four species which occur in the Atlantic and Pacific Oceans. Thyonella mexicana is the only species known to occur in the Pacific Ocean. The main morphological characters used to distinguish Thyonella species are their dermal ossicles. Since the differences among these characters are subtle, this contribution provides a detailed description and comparison of the ossicle assemblage of the concerned taxa. In addition, description of the internal morphology of three of the concerned species is also provided. Further, this study reports on the first record of Thyonella sabanillaensis for the Southwestern Atlantic. A worldwide revision of the distributional records of Thyonella species is presented and their taxonomy is discussed, concluding that some traditional taxonomic characters should be used cautiously. A brief discussion about the importance of SEM analysis is also provided. 


Zootaxa ◽  
2021 ◽  
Vol 4942 (3) ◽  
pp. 301-338
Author(s):  
JESSÉ MIRANDA DE FIGUEIREDO-FILHO ◽  
ALEXANDRE P. MARCENIUK ◽  
ANDERSON FEIJÓ ◽  
RAQUEL SICCHA-RAMIREZ ◽  
GIOVANA S. RIBEIRO ◽  
...  

Centropomus Lacépède, 1802 comprises 13 species of the fishes popularly knows as snooks, distributed in both Atlantic and Pacific coasts of America. Despite several studies on the group, conflicting taxonomic classifications still exist, including overlapping diagnostic characters, rendering species diagnoses extremely difficult. Herein, we review the taxonomy of Centropomus to elucidate species identities, redefine their diagnoses and to assess interspecific relationships based on the examination of 376 specimens. The study included complementary approaches, as analyses of external morphologic characters, linear and geometric morphometrics, and molecular analyses. Forty-nine characters were used for external morphology, 17 discrete plus 32 linear measurements. Shape and size were analyzed through geometric morphometrics of 185 specimens in lateral view. Partial sequences of the gene cytochrome c oxidase I were obtained for 129 specimens representing 11 species. Based on the consistent results retrieved from the morphologic and molecular analyses, we recognized six species of Centropomus from the Atlantic coast (C. ensiferus, C. irae, C. parallelus, C. pectinatus, C. poeyi and C. undecimalis). Centropomus mexicanus is treated as a junior synonym of C. parallelus. Six species from the Pacific coast are also tentatively recognized (C. armatus, C. medius, C. nigrescens, C. robalito, C. unionensis, and C. viridis), however further studies on the Pacific species are still needed. Information on type material, diagnosis, distribution, and taxonomic comments are provided for each species. An identification key to the species of Centropomus is presented. 


Phytotaxa ◽  
2017 ◽  
Vol 317 (1) ◽  
pp. 17 ◽  
Author(s):  
LILÍ MARTÍNEZ-DOMÍNGUEZ ◽  
FERNANDO NICOLALDE-MOREJÓN ◽  
DENNIS WM. STEVENSON

Several Ceratozamia populations from the “Carso Huasteco” region in Mexico have a controversial circumscription and have been historically identified as Ceratozamia fuscoviridis. In this paper, we present a review of the taxonomic history of this species and provide taxa circumscriptions based on analyses of herbarium specimens from this region and supplemented with fieldwork. For this, we have studied qualitative and quantitative morphological variation at population level. We recognize two species in this group: C. fuscoviridis and a new species, C. chamberlainii. Here, we provide two lines of qualitative and quantitative morphological evidence showing that plants of C. chamberlainii from southern San Luis Potosí to northern Hidalgo are distinct from C. fuscoviridis of central Hidalgo east of Veracruz. These species can be identified by leaflet form, leaf emergence color, color of the ovulate strobilus, and form of the megasporophyll, along with a combination of quantitative morphological characters.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1712 ◽  
Author(s):  
Shaleyla Kelez ◽  
Ximena Velez-Zuazo ◽  
Aldo S. Pacheco

Hybridization among sea turtle species has been widely reported in the Atlantic Ocean, but their detection in the Pacific Ocean is limited to just two individual hybrid turtles, in the northern hemisphere. Herein, we report, for the first time in the southeast Pacific, the presence of a sea turtle hybrid between the green turtleChelonia mydasand the hawksbill turtleEretmochelys imbricata.This juvenile sea turtle was captured in northern Peru (4°13′S; 81°10′W) on the 5thof January, 2014. The individual exhibited morphological characteristics ofC. mydassuch as dark green coloration, single pair of pre-frontal scales, four post-orbital scales, and mandibular median ridge, while the presence of two claws in each frontal flipper, and elongated snout resembled the features ofE. imbricata. In addition to morphological evidence, we confirmed the hybrid status of this animal using genetic analysis of the mitochondrial gene cytochrome oxidase I, which revealed that the hybrid individual resulted from the cross between a femaleE. imbricataand a maleC. mydas. Our report extends the geographical range of occurrence of hybrid sea turtles in the Pacific Ocean, and is a significant observation of interspecific breeding between one of the world’s most critically endangered populations of sea turtles, the east PacificE. imbricata, and a relatively healthy population, the east PacificC. mydas.


2021 ◽  
Vol 758 ◽  
Author(s):  
Ján Kodada ◽  
Dávid Selnekovič ◽  
Manfred A. Jäch ◽  
Katarína Goffová ◽  
Peter Vďačný

The species of Elmomorphus Sharp, 1888 occurring in Japan and Korea are redescribed and illustrated: E. brevicornis Sharp, 1888 (Japan, Korea) and E. amamiensis Nomura, 1959 (Japan). The standard barcoding fragment of the mitochondrial gene coding for cytochrome c oxidase subunit I (COI) was sequenced and used together with morphological characters to delimit the taxonomic boundaries of the two species. To assess their morphometric variation, eight morphometric characters were measured and statistically evaluated using principal component analysis. The two species of Elmomorphus formed distinct and well-separated clusters in the COI tree. Their interspecific divergence is very high, ranging from 22.7 to 23.9%. On the other hand, morphometric characters, including those previously presumed to be diagnostic, overlap and per se do not allow unambiguous species identification. Reliable morphological distinguishing characters are described for males and females. Molecular data along with the morphological evidence strongly confirm the species status of E. amamiensis. An identification key to the Japanese and Korean species is provided.


Author(s):  
AZAD TEIMORI ◽  
MINA MOTAMEDI ◽  
ATEFEH IRANMANESH

Among the skeletal elements in fishes, the urohyal bone which lies in the lower part of the head - the central part of the mandibular skeleton- has proved to be of special significance in fish systematics. The urohyal bone is considered to be a synapomorphic structure in teleostean fish. The urohyal bone of six brackish water Aphanius species (i.e., Aphanius hormuzensis, A. stoliczkanus, A. furcatus, A. ginaonis, A. mento, A. sirhani) was compared using morphological description and linear measurements to explore the effectiveness of urohyal bone morphology in the separation of the Aphanius species. Description of the urohyal bones and their morphological variation allowed identification of the A. furcatus, A. mento and A. sirhani from their relatives. Moreover, the UH.UL separates significantly A. dispar and A. ginaonis, and the MH.UL discriminates significantly A. mento from others studied relatives. Discriminant function analysis (DFA) separated the studied species with high classification success (overall mean 94.7%). These results suggest the power of urohyal bone morphology in separating of the Aphanius species analyzed, and highlighting the taxonomic value of the urohyal bone. By considering the phylogenetic relationships among the studied species, it can be concluded that the observed variation in their urohyal morphology is largely consistent with their phylogeny. This indicated that at least some morphological characters in the shape of urohyal bone in Aphanius are encoded probably by genetic factors, which can be used for species discrimination.


Author(s):  
Paula Braga Gomes ◽  
Renata Schama ◽  
Antônio Mateo Solé-Cava

Phymactis papillosa is a rocky shore sea anemone that is commonly found in the Pacific Ocean, from the Gulf of California to Tierra del Fuego, and in the Mar del Plata region, Argentina. The genus Phymactis is closely related to Bunodosoma and, due to character plasticity, a number of misidentifications have occurred. Therefore, the presence of P. papillosa in Argentina has been doubted but the matter had not been investigated in detail. Here we analyse P. papillosa specimens from Argentina and compare them, using molecular and morphological markers, to specimens from the species' type locality. In a phylogenetic analysis using 19 allozyme markers and ribosomal internal transcribed spacers sequences of different sea anemone genera, including all West Atlantic Bunodosoma species, we have found that the specimens from Argentina were genetically divergent from P. papillosa from Chile and closely related to West Atlantic Bunodosoma species. The genetic and morphological analyses indicate that those specimens belong to a new species of the genus Bunodosoma, described here as B. zamponii sp. nov.


Phytotaxa ◽  
2013 ◽  
Vol 130 (1) ◽  
pp. 1 ◽  
Author(s):  
Steven G Newmaster ◽  
YU-JING LIU ◽  
XIAN-JIN WU ◽  
YUE LIU ◽  
Subramanyam Ragupathy ◽  
...  

Pinellia hunanensis, a new species from China, is described and illustrated. A key for the identification of all Pinellia species in China, Korea and Japan is included. A detrended correspondence analysis identified 6 groups of taxa including the new species. From the 20 samples, analyzing 38 morphological characters. A discriminant function analysis was used to rigorously test the classification of specimens provided in the cluster analysis. DNA barcoding provided phylogenetic support using NJ and Bayesian methods to distinguish all six taxa including the putative new species. This study provides preliminary evidence of morphometric variation within and among species of Pinellia, which allows further development of hypothesis concerning species boundaries. Discussions concerning medicinal product substitution within the genus Pinellia are presented in the context of conservation initiatives of species in China.


2021 ◽  
Vol 775 ◽  
pp. 185-196
Author(s):  
Odile Volonterio ◽  
Rodrigo Ponce de León

Coelogynoporidae (Platyhelminthes) includes comparatively large and slender Proseriata, usually occurring in shallow benthic environments. Coelogynopora Steinböck, 1924 is the most frequently reported genus and the one with the highest species diversity. Notwithstanding that, the genus has never been reported from the Southern Hemisphere. A recent analysis of sediment from the Magellan Strait shores (Chile) resulted in the discovery of a new species of Coelogynopora, the first representative of the genus to be found in austral waters. The new species is defined by the following combination of characters: sclerotised copulatory system consisting of a slender, ventrally curved stylet with a broad base and three pairs of symmetrically arranged spines, the proximal ends of which are fused laterally to the base of the stylet; distal ends of the three pairs of spines hooked, with apophyses at progressively longer distances from the tip; accessory spines and solar organ absent. Based on the morphological characters, the new species appears to be more related to species from the Pacific Ocean than to those from the Atlantic Ocean. The present work suggests a vast biogeographic disjunction in the genus Coelogynopora, which may be described as a bipolar or amphitropical pattern of distribution.


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