MORPHOMETRIC COMPARISON OF CHARACIDAE FISH WHEN n < p
DANNY VILLEGAS RIVAS *
Faculty of Forestry and Environmental Engineering, National University of Jaén, Cajamarca, Peru.
MANUEL MILLA PINO
Faculty of Civil Engineering. National University of Jaén, Cajamarca, Peru.
TOMÁS RODRÍGUEZ BEAS
Postgraduate School, César Vallejo University, Peru.
MIRYAM LORA LOZA
Postgraduate School, César Vallejo University, Peru.
MARTÍN GRADOS VASQUEZ
Postgraduate School, César Vallejo University, Peru.
CESAR OSORIO CARRERA
Postgraduate School, Continental University, Lima, Peru.
RICARDO SHIMABUKU YSA
Faculty of Mechanical and Electrical Engineering, National University of Jaén, Cajamarca, Peru.
RIVER CHÁVEZ SANTOS
Faculty of Economic and Administrative Sciences, ‘Toribio Rodríguez de Mendoza’ National University of Amazonas, Perú.
LUIS RAMÍREZ CALDERÓN
Postgraduate School, César Vallejo University, Peru.
YDALIA VELÁSQUEZ CASANA
Postgraduate School, National University of Trujillo, Perú.
WILFREDO RUIZ CAMACHO
Faculty of Forestry and Environmental Engineering, National University of Jaén, Cajamarca, Peru.
HUGO EGOCHEAGA CASAS
Faculty of Administration and Business, Technological University of Perú, Peru.
CLELIA JIMA CHAMIQUIT
Faculty of Health Sciences, Toribio Rodríguez de Mendoza’ National University of Amazonas, Perú.
ROBERTO PACHECO ROBLES
Faculty of Accounting and International Business and Tourism, National Autonomous University of Alto Amazonas, Perú.
ZADITH GARRIDO CAMPAÑA
Faculty of Civil Engineering. National University of Jaén, Cajamarca, Peru.
ERICK DELGADO BAZAN
Faculty of Civil Engineering. National University of Jaén, Cajamarca, Peru.
*Author to whom correspondence should be addressed.
Abstract
Currently, great importance has been given to the study of external morphology, especially in fish, when it is used as a means of identifying hybrids. This paper considers a LASSO model based on the truss protocol to compare morphological covarion patterns between specimens of Colossoma macropomum and the hybrid C. macropomum (♀) x P. orinoquensis (♂). In this study, 25 specimens of C. macropomum and 20 specimens of the hybrid C. macropomum (♀) x P. orinoquensis (♂), respectively, were analyzed. The method "Truss protocol" or "trusses" Strauss and Bookstein (1982) was used. LASSO model achieved to reduce the mean squared error. The final model obtained contains only seven covariates. LASSO model fitted on the morphological covariation patterns between specimens of C. macropomum and the hybrid C. macropomum (♀) x P. orinoquensis (♂) showed a good fit and allowed to correctly classify most of the specimens. Differences were observed in the area of the head and in the anterior part of the fish evidenced in covariates associated with hydrodynamic abilities and with foraging.Morphometry
Keywords: Morphometry, truss protocol, fishes, lambda, shrinkage regression.