Taxonomic revision of Bunocephalus coracoideus complex (Siluriformes: Aspredinidae) using molecular and morphological approaches

• Grant number: 24/07526-2
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: August 20, 2024
• End date: January 19, 2025
• Field of knowledge: Biological Sciences - Zoology - Taxonomy of Recent Groups
• Principal Investigator: Claudio de Oliveira
• Grantee: Jefferson Luan Crispim Rodrigues
• Supervisor: Mark Sabaj Perez
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: Drexel University, United States
• Associated to the scholarship: 23/01862-8 - Phylogenomic of members of the family Aspredinidae (Siluriformes: Ostariophysi), BP.MS

Abstract

The banjo catfish family Aspredinidae is characterized by having a distinctively shaped body that is anteriorly enlarged and dorsoventrally compressed with a narrow caudal peduncle. Aspredinidae is widely distributed throughout South American lowlands, with most species inhabiting freshwater rivers, streams, and lakes and some representatives of the tribe Aspredinini inhabiting coastal brackish and marine waters. The family comprises 49 valid species, distributed among three subfamilies: Aspredininae, Hoplomyzontinae, and Pseudobunocephalinae. One of the most common and widely distributed aspredinid species in the Amazon basin is Bunocephalus coracoideus (Cope 1874), which has been reported from all South American countries north of Paraguay, and is easily diagnosed by having a very large posterior process on the coracoids, seven to eight branched caudal-fin rays, the height of the head representing 45,9 to 67% of head length, and a reduced connection between the last dorsal-fin ray and the dorsum. The wide distribution of Bunocephalus coracoideus plus recent molecular data suggest that potentially several cryptic, undescribed species are hiding within this widespread morphotype. The main purpose of this project is to integrate molecular and morphological approaches to recognize and diagnose these species. For the molecular analysis, the COI region will be sequenced, and species delimitation will be performed using ASAP and PTP methods. For the morphological analysis, meristic counts and measurements will be obtained manually and osteological comparisons among lineages will be made using micro-computed tomography (CT).