Guianacara dacrya, a new species from the rio Branco and Essequibo River drainages of the Guiana Shield (Perciformes: Cichlidae)

Arbour, Jessica H.; López‐Fernández, Hernán

doi:10.1590/s1679-62252011000100006

Cited by 9 publications

(5 citation statements)

References 12 publications

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“…Obs.). This is despite the considerable ecological‐ and ontogenetic‐based variation in shape within each data set (Arbour, Hardie & Hutchings ; Arbour & López‐fernández ). These data sets did not appear to have the most inherent shape structure: PC1 and PC2 summarized a cumulative total of 61·1% and 58·9% of shape variation in the AC and GD data sets, compared to 46·8% in TY, 38·8% in HS and 65·6% in PR.…”

Section: Discussionmentioning

confidence: 95%

Incomplete specimens in geometric morphometric analyses

Arbour

Brown

2013

Methods Ecol Evol

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Summary The analysis of morphological diversity frequently relies on the use of multivariate methods for characterizing biological shape. However, many of these methods are intolerant of missing data, which can limit the use of rare taxa and hinder the study of broad patterns of ecological diversity and morphological evolution. This study applied a mutli‐data set approach to compare variation in missing data estimation and its effect on geometric morphometric analyses across taxonomically variable groups, landmark position and sample sizes. Missing morphometric landmark data were simulated from five real, complete data sets, including modern fish, primates and extinct theropod dinosaurs. Missing landmarks were then estimated using several standard approaches and a geometric‐morphometric‐specific method. The accuracy of missing data estimation was determined for each estimation method, landmark position and morphological data set. Procrustes superimposition was used to compare the eigenvectors and principal component scores of a geometric morphometric analysis of the original landmark data, to data sets with A) missing values estimated, or B) simulated incomplete specimens excluded, for varying levels of specimens incompleteness and sample sizes. Standard estimation techniques were more reliable estimators and had lower impacts on morphometric analysis compared with a geometric‐morphometric‐specific estimator. For most data sets and estimation techniques, estimating missing data produced a better fit to the structure of the original data than exclusion of incomplete specimens, and this was maintained even at considerably reduced sample sizes. The impact of missing data on geometric morphometric analysis was disproportionately affected by the most fragmentary specimens. Missing data estimation was influenced by variability of specific anatomical features and may be improved by a better understanding of shape variation present in a data set. Our results suggest that the inclusion of incomplete specimens through the use of effective missing data estimators better reflects the patterns of shape variation within a data set than using only complete specimens; however, the effectiveness of missing data estimation can be maximized by excluding only the most incomplete specimens. It is advised that missing data estimators be evaluated for each data set and landmark independently, as the effectiveness of estimators can vary strongly and unpredictably between different taxa and structures.

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Section: Discussionmentioning

confidence: 95%

Incomplete specimens in geometric morphometric analyses

Arbour

Brown

2013

Methods Ecol Evol

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“…The supraneural bones, formerly known as predorsal spines, are a character of great importance in the phylogenetic classification of Teleost fishes ( Fink and Fink 1981 ; Mabee 1988 ). In some groups of the family Cichlidae , the number of supraneural bones has been used to separate genera and species ( Gosse 1975 ; López-Fernández and Taphorn 2004 ; López-Fernández et al 2006 ; Sparks and Stiassny 2010 ; Arbour and López-Fernández 2011 ; Martinez et al 2015 ). According to our review, it is not common to find members of the Cichlidae family in America that have three supraneural bones, since most of the Neotropical species have only two or sometimes just one element (e.g., Kullander 1986 , 1998 ; López-Fernández et al 2005 ; Kullander and Ferreira 2006 ; Chakrabarty and Sparks 2007 ).…”

Section: Discussionmentioning

confidence: 99%

A new species of Astronotus (Teleostei, Cichlidae) from the Orinoco River and Gulf of Paria basins, northern South America

Lozáno¹,

Lasso-Alcalá

Bittencourt³

et al. 2022

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Based on morphological and molecular analysis of Astronotus species, a new species is described from the Orinoco River and Gulf of Paria basins in Venezuela and Colombia. Morphologically, it differs from Astronotus crassipinnis and Astronotus ocellatus in pre-orbital depth, caudal peduncle depth, head width, and caudal peduncle length, with significant differences in average percentage values. Osteologically, it differs from the two described species by lacking a hypurapophysis on the parahypural bone (hypural complex) and having two or three supraneural bones. Another characteristic that helps diagnose the new species is the morphology of the sagitta otolith, which is oval with crenulated dorsal and ventral margins and a rounded posterior edge. Genetically, the new species is distinct from all the other lineages previously proposed for the genus, delimited by five single locus species delimitation methods, and also has unique diagnostic nucleotides. Phylogenetic analyses support the monophyly of the new species as well as all other species/lineages. Astronotus species have considerable genetic, anatomical, and sagitta otolith shape differences, but have few significant traditional morphometric and meristic differences, because there is high variability in counts of spines, soft dorsal-fin rays, and lateral-line scales. It is clear that this new species is genetically and anatomically differentiated from all other species within the genus, and deserves recognition as a new valid species.

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“…For example, Guianacara, although the sister group to Mazarunia, has a rather stereotyped morphology that makes differences between species very subtle (e.g. López-Fernández et al, 2006;Arbour & López-Fernández, 2011). Differences in the lower pharyngeal jaw are particularly interesting, because they may suggest differences in trophic ecology as well.…”

Section: Discussionmentioning

confidence: 99%

Phylogenetic diagnosis and expanded description of the genus Mazarunia Kullander, 1990 (Teleostei: Cichlidae) from the upper Mazaruni River, Guyana, with description of two new species

López‐Fernández¹,

Taphorn²,

Liverpool³

2012

Neotrop. ichthyol.

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We expand the description of the genus Mazarunia Kullander, 1990, explore morphological diagnostic characters for the genus and for its sister-group relationship with Guianacara Kullander & Nijssen, 1989 in a phylogenetic context, expand the description of M. mazarunii and describe two new species. Mazarunia can be diagnosed by the combination of numerous anatomical traits, including the unique loss of infraorbital 6, the configuration of the first epibranchial in two of the species, a well-developed posteroventral lateral expansion of the palatine that is largely contiguous with the ectopterygoid, the absence of a suture between the hyomandibular and the metapterygoid, the absence of an interarcual cartilage, fourth ceratobranchial with 2 or 3 tooth plates, a caudally scaled interoperculum, equal-sized scales in the ventral and lateral chest regions, a simple, disjunct pattern of lateral line squamation, and smooth preopercle, supracleithrum and extrascapula. Species of Mazarunia can be further distinguished from species of their sistergenus Guianacara by their distinct color patterns. Mazarunia charadrica, new species, can be distinguished from other species of Mazarunia, among other characters, by approximately equal uncinate process and anterior arm and reduced anteroventral expansion of epibranchial 1 (vs. uncinate process narrower and complete anteroventral expansion in the other two species), a dorso-ventrally flattened maxillary process of the palatine (vs. cylindrical in the other two species), cycloid (vs. ctenoid) scales in the opercular, postorbital, lateral chest and anal-genital regions, the absence of a mid-lateral spot, and a diffuse dark area covering the dorsal portion of the head giving the impression of a "black cap". Mazarunia charadrica has a unique juvenile pattern of seven vertical dark bars partially preserved in adults. Bars 3-6 in antero-caudal direction are most visible in juveniles and medium-sized specimens but become fainter and almost disappear in adults. Many specimens show only bar number 3 (midlateral bar). Mazarunia mazarunii can be distinguished from all other species of Mazarunia by the presence of two foramina (vs. one) on the lateral face of the ascending process of the premaxilla, a lachrymal bone that is longer than deep (vs. deeper than long), an infraorbital 3 that is contiguous but not overlapping with the lachrymal (vs. overlapping), ctenoid scales (vs. cycloid) on the subopercle, interopercle and chest, and by its unique coloration, including complete suborbital and supraorbital stripes, and being the only species of Mazarunia with a discernible lateral band formed by the mid-line blotching pattern associated with lateral bars. In large adults, M. mazarunii has a black or dark bar behind the head that produces the impression of a collar. Mazarunia pala, new species, can be distinguished from its congeners by the absence of a parhypurapophysis, the presence of a dorsal-fin scaly pad with ctenoid scales (vs. no scaly pad in M. charadrica and M. mazarunii), a small sub...

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Guianacara dacrya, a new species from the rio Branco and Essequibo River drainages of the Guiana Shield (Perciformes: Cichlidae)

Cited by 9 publications

References 12 publications

Incomplete specimens in geometric morphometric analyses

Incomplete specimens in geometric morphometric analyses

A new species of Astronotus (Teleostei, Cichlidae) from the Orinoco River and Gulf of Paria basins, northern South America

Phylogenetic diagnosis and expanded description of the genus Mazarunia Kullander, 1990 (Teleostei: Cichlidae) from the upper Mazaruni River, Guyana, with description of two new species

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Guianacara dacrya, a new species from the rio Branco and Essequibo River drainages of the Guiana Shield (Perciformes: Cichlidae)

Cited by 9 publications

References 12 publications

Incomplete specimens in geometric morphometric analyses

Incomplete specimens in geometric morphometric analyses

﻿A new species of Astronotus (Teleostei, Cichlidae) from the Orinoco River and Gulf of Paria basins, northern South America

Phylogenetic diagnosis and expanded description of the genus Mazarunia Kullander, 1990 (Teleostei: Cichlidae) from the upper Mazaruni River, Guyana, with description of two new species

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A new species of Astronotus (Teleostei, Cichlidae) from the Orinoco River and Gulf of Paria basins, northern South America