Morphometric and Taxonomic Analysis of Cetopsorhamdia
Faculty Mentor Name
Eric Thomas
Research or Creativity Area
Natural Sciences
Abstract
As part of an ongoing effort to develop a species journal for Cetopsorhamdia, this study aims to generate detailed morphometric data to support species identification and comparison within the genus. Cetopsorhamdia is a genus of small freshwater catfishes belonging to the family Heptapteridae. These fishes are widely distributed across diverse South American river systems, including the Amazon, Orinoco, and Paraná basins, where they typically inhabit clear-water environments with abundant leaf litter.
To characterize morphological variation, a series of morphometric measurements were collected for each specimen following standardized point-to-point protocols based on an established measurement chart and corresponding anatomical reference figure. All measurements were taken in millimeters using a digital caliper to ensure precision and consistency. For each morphometric parameter, three independent measurements were recorded per specimen, and the average value was calculated to minimize measurement error and improve accuracy in proportional analysis.
Certain measurements, including humeral process length, pectoral-fin spine length, adipose-fin base length, and caudal peduncle depth, were excluded due to limitations in specimen condition. In addition to linear morphometrics, qualitative traits such as body coloration were documented to assess potential variation among individuals. Meristic data were also collected by counting numerous fin rays for each specimen, providing an additional dataset to evaluate similarities and differences within and between individuals.
These morphometric and meristic analyses contribute to a more refined understanding of intraspecific variation and support ongoing taxonomic efforts within Cetopsorhamdia. This study provides foundational data that may aid in future species delimitation and comparative analyses within the family Heptapteridae.
Morphometric and Taxonomic Analysis of Cetopsorhamdia
As part of an ongoing effort to develop a species journal for Cetopsorhamdia, this study aims to generate detailed morphometric data to support species identification and comparison within the genus. Cetopsorhamdia is a genus of small freshwater catfishes belonging to the family Heptapteridae. These fishes are widely distributed across diverse South American river systems, including the Amazon, Orinoco, and Paraná basins, where they typically inhabit clear-water environments with abundant leaf litter.
To characterize morphological variation, a series of morphometric measurements were collected for each specimen following standardized point-to-point protocols based on an established measurement chart and corresponding anatomical reference figure. All measurements were taken in millimeters using a digital caliper to ensure precision and consistency. For each morphometric parameter, three independent measurements were recorded per specimen, and the average value was calculated to minimize measurement error and improve accuracy in proportional analysis.
Certain measurements, including humeral process length, pectoral-fin spine length, adipose-fin base length, and caudal peduncle depth, were excluded due to limitations in specimen condition. In addition to linear morphometrics, qualitative traits such as body coloration were documented to assess potential variation among individuals. Meristic data were also collected by counting numerous fin rays for each specimen, providing an additional dataset to evaluate similarities and differences within and between individuals.
These morphometric and meristic analyses contribute to a more refined understanding of intraspecific variation and support ongoing taxonomic efforts within Cetopsorhamdia. This study provides foundational data that may aid in future species delimitation and comparative analyses within the family Heptapteridae.
