Examinando por Autor "Indurain, Maria J"

Mostrando 1 - 2 de 2
  • Miniatura
    Ítem
    Integrating Egg Case Morphology and DNA Barcoding to Discriminate South American Catsharks, Schroederichthys bivius and S. chilensis (Carcharhiniformes: Atelomycteridae)
    (MDPI, 2025) Bustamante, Carlos; Vargas-Caro, Carolina; Indurain, Maria J; Silva, Gabriela
    Catsharks are benthic elasmobranchs that share spatial niches with littoral and demersal bony fishes. The genus Schroederichthys includes five species, two of which, S. chilensis and S. bivius, occur in the waters of Chile. These species are morphologically similar and are often misidentified because of their overlapping external features and color patterns. To improve species discrimination, we analyzed the egg case morphology of both species based on 36 egg cases (12 S. chilensis, 24 S. bivius) collected from gravid females captured as bycatch in artisanal fisheries between Iquique and Puerto Montt (July–December 2021). Nine morphometric variables were measured and standardized using the total egg case length. Although the egg cases were similar in general appearance, multivariate analyses revealed significant interspecific differences, with egg case height and anterior border width emerging as the most diagnostic variables. Linear discriminant analysis achieved a 100% classification accuracy within this dataset. To confirm species identity, 24 tissue samples (12 per species) were sequenced for the mitochondrial cytochrome c oxidase subunit I (COI) gene. The haplotypes corresponded to previously published sequences from Chile (S. chilensis) and Argentina (S. bivius), with reciprocal monophyly and 100% bootstrap support. While COI barcoding provided robust confirmation, the core contribution of this study lies in the identification of species-specific egg case morphometrics. Together, these findings establish a dual-track toolkit, egg case morphology for primary discrimination and COI barcodes for confirmatory validation, that can be incorporated into bycatch monitoring and biodiversity assessments, supporting the conservation of poorly known catsharks in the Southeast Pacific.
  • Miniatura
    Ítem
    New record of Frilled shark Chlamydoselachus anguineus Garman, 1884 (Chondrichthyes: Hexanchiformes) in the South Pacific Ocean
    (PeerJ Inc., 2025) Indurain, Maria J; Mancilla, Angel; Brizuela, Leandro; Vargas-Caro, Carolina; Bustamante, Carlos
    Frilled sharks are rarely observed and limited information is available regarding their life history. The global number of records for these sharks does not exceed 40, with most sightings reported in the Western Pacific Ocean. In 1976, one specimen was recorded for the first time in the South East Pacific Ocean; however, this study provides new evidence for the presence of Chlamydoselachus anguineus in Chilean waters, extending its distribution range 850 km south of the previous record. The morphological features of all specimens from Chile are discussed, supplementing previous observations and adding to the existing knowledge on this species in the Pacific Ocean.