Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)

The genus Tlaloc contains four valid species and forms part of the family Profundulidae, a group of small freshwater fishes endemic to the Mesoamerican region. The objective of this study was to provide a detailed description of the urohyal bone of two species of Tlaloc—Tlaloc labialis (Günther, 186...

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Main Authors: Alejandro Padilla-Sánchez, Sara E. Domínguez-Cisneros, Ernesto Velázquez-Velázquez, Abraham Kobelkowsky
Format: Article
Language:English
Published: Pensoft Publishers 2025-07-01
Series:Acta Ichthyologica et Piscatoria
Online Access:https://aiep.pensoft.net/article/151622/download/pdf/
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author Alejandro Padilla-Sánchez
Sara E. Domínguez-Cisneros
Ernesto Velázquez-Velázquez
Abraham Kobelkowsky
author_facet Alejandro Padilla-Sánchez
Sara E. Domínguez-Cisneros
Ernesto Velázquez-Velázquez
Abraham Kobelkowsky
author_sort Alejandro Padilla-Sánchez
collection DOAJ
description The genus Tlaloc contains four valid species and forms part of the family Profundulidae, a group of small freshwater fishes endemic to the Mesoamerican region. The objective of this study was to provide a detailed description of the urohyal bone of two species of Tlaloc—Tlaloc labialis (Günther, 1866) and T. candalarius (Hubbs, 1924)—and to evaluate the usefulness of this osteological structure in delimiting these taxa. The urohyal bone is a single bony structure located in the ventral part of the head in both species and is the result of ossification of an unpaired tendon of the sternohyoideus muscle. Data from cleared and double-stained museum specimens of the focal taxa were analyzed, including morphometric measurements of each urohyal bone taken using an ocular micrometer connected to a stereomicroscope. We found the most notable difference between the two species was the height of the urohyal neck, which was significantly narrower in T. candalarius (6.66%–11.11% of total urohyal length) than in T. labialis (13.15%–25%) based on the non-parametric Mann–Whitney U test. Our results show that measuring the urohyal bone offers a reliable and attractive alternative for taxonomic determination of Tlaloc labialis vs. T. candalarius due to the operational simplicity and speed of such measures. Our work also highlights the utility of more detailed osteological analyses in taxonomic and systematic studies of profundulids.
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spelling doaj-art-e51fe9817bdc4711bc2203fa988ffdf42025-08-20T03:15:30ZengPensoft PublishersActa Ichthyologica et Piscatoria1734-15152025-07-015513313710.3897/aiep.55.151622151622Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)Alejandro Padilla-Sánchez0Sara E. Domínguez-Cisneros1Ernesto Velázquez-Velázquez2Abraham Kobelkowsky3Universidad de Ciencias y Artes de ChiapasUniversidad de Ciencias y Artes de ChiapasUniversidad de Ciencias y Artes de ChiapasUniversidad Autónoma MetropolitanaThe genus Tlaloc contains four valid species and forms part of the family Profundulidae, a group of small freshwater fishes endemic to the Mesoamerican region. The objective of this study was to provide a detailed description of the urohyal bone of two species of Tlaloc—Tlaloc labialis (Günther, 1866) and T. candalarius (Hubbs, 1924)—and to evaluate the usefulness of this osteological structure in delimiting these taxa. The urohyal bone is a single bony structure located in the ventral part of the head in both species and is the result of ossification of an unpaired tendon of the sternohyoideus muscle. Data from cleared and double-stained museum specimens of the focal taxa were analyzed, including morphometric measurements of each urohyal bone taken using an ocular micrometer connected to a stereomicroscope. We found the most notable difference between the two species was the height of the urohyal neck, which was significantly narrower in T. candalarius (6.66%–11.11% of total urohyal length) than in T. labialis (13.15%–25%) based on the non-parametric Mann–Whitney U test. Our results show that measuring the urohyal bone offers a reliable and attractive alternative for taxonomic determination of Tlaloc labialis vs. T. candalarius due to the operational simplicity and speed of such measures. Our work also highlights the utility of more detailed osteological analyses in taxonomic and systematic studies of profundulids.https://aiep.pensoft.net/article/151622/download/pdf/
spellingShingle Alejandro Padilla-Sánchez
Sara E. Domínguez-Cisneros
Ernesto Velázquez-Velázquez
Abraham Kobelkowsky
Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)
Acta Ichthyologica et Piscatoria
title Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)
title_full Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)
title_fullStr Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)
title_full_unstemmed Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)
title_short Comparative morphology of the urohyal bone between two species of the genus Tlaloc (Actinopterygii, Cyprinodontiformes, Profundulidae)
title_sort comparative morphology of the urohyal bone between two species of the genus tlaloc actinopterygii cyprinodontiformes profundulidae
url https://aiep.pensoft.net/article/151622/download/pdf/
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