Latest Articles from Vertebrate Zoology Latest 3 Articles from Vertebrate Zoology https://vertebrate-zoology.arphahub.com/ Thu, 28 Mar 2024 11:39:38 +0200 Pensoft FeedCreator https://vertebrate-zoology.arphahub.com/i/logo.jpg Latest Articles from Vertebrate Zoology https://vertebrate-zoology.arphahub.com/ Mystus celator, a new species of catfish from northern Myanmar (Actinopterygii: Siluriformes: Bagridae) https://vertebrate-zoology.arphahub.com/article/110875/ Vertebrate Zoology 73: 981-990

DOI: 10.3897/vz.73.e110875

Authors: Heok Hee Ng, Maurice Kottelat

Abstract: Abstract Mystus celator sp. nov. is described from the Irrawaddy River drainage in northern Myanmar. It can be distinguished from congeners in having a combination of: three equally dark longitudinal stripes separated by two pale interspaces on sides of body; round, dark tympanic spot; ovoid, dark spot on caudal peduncle; length of adipose-fin base 18.0–23.3% SL; angle of predorsal profile 21–24°; posterior cranial fontanelle not reaching base of supraoccipital process; 25–30 rakers on the first branchial arch; and 35–36 vertebrae. The identity of Mystus pulcher is fixed with the designation of a lectotype.

HTML

XML

PDF

]]>
Research Article Thu, 2 Nov 2023 09:07:29 +0200
Evolution in the dark: Unexpected genetic diversity and morphological stasis in the blind, aquifer-dwelling catfish Horaglanis https://vertebrate-zoology.arphahub.com/article/98367/ Vertebrate Zoology 73: 57-74

DOI: 10.3897/vz.73.e98367

Authors: Rajeev Raghavan, Remya L. Sundar, C.P. Arjun, Ralf Britz, Neelesh Dahanukar

Abstract: The lateritic aquifers of the southern Indian state of Kerala harbour a unique assemblage of enigmatic stygobitic fishes which are encountered very rarely, only when they surface during the digging and cleaning of homestead wells. Here, we focus on one of the most unusual members of this group, the catfish Horaglanis, a genus of rarely-collected, tiny, blind, pigment less, and strictly aquifer-residing species. A six-year exploratory and citizen-science backed survey supported by molecular phylogenetic analysis reveals novel insights into the diversity, distribution and population structure of Horaglanis. The genus is characterized by high levels of intraspecific and interspecific genetic divergence, with phylogenetically distinct species recovered above a 7.0% genetic-distance threshold in the mitochondrial cytochrome oxidase subunit 1 gene. Contrasting with this deep genetic divergence, however, is a remarkable stasis in external morphology. We identify and describe a new cryptic species, Horaglanis populi, a lineage that is the sister group of all currently known species. All four species are represented by multiple haplotypes. Mismatch distribution reveals that populations have not experienced recent expansions.

HTML

XML

PDF

]]>
Research Article Wed, 25 Jan 2023 14:53:04 +0200
Developmental osteology of Ictalurus punctatus and Noturus gyrinus (Siluriformes: Ictaluridae) with a discussion of siluriform bone homologies https://vertebrate-zoology.arphahub.com/article/85144/ Vertebrate Zoology 72: 661-727

DOI: 10.3897/vz.72.e85144

Authors: Kole M. Kubicek

Abstract: Abstract The skeleton of Siluriformes is characterized by several autapomorphies, including secondary absence, extreme modification, and purported fusion of several ossifications. Although well documented in adults, information on skeletal development in catfishes is relatively sparse and typically focused on particular regions of the skeleton (e.g., Weberian apparatus). To further our understanding of the siluriform skeleton, I document the development of the entire skeleton in two ictalurid species, Ictalurus punctatus (channel catfish) and Noturus gyrinus (tadpole madtom) from five days pre-hatch to adult. I reexamine the homologies of bones previously hypothesized to represent compound elements in catfishes as well as an additional element only known to occur in some ictalurids. Development of the skeleton is complete in I. punctatus at 22.4 mm SL and almost complete in N. gyrinus (except dorsal- and anal-fin distal radials) at 14.1 mm SL. No signs of ontogenetic fusion were observed in any of the purported compound elements. Previous hypotheses of the homology of these elements and of additional ossifications are reviewed in light of developmental information obtained herein. No dermal parietal component is present at any stage in the so-called parieto-supraoccipital. The bone is the supraoccipital which ossifies from two lateral centers of ossification which later fuse, rather than from a median center. The ‘posttemporo-supracleithrum’ originates from a single center of ossification and represents the supracleithrum. The posttemporal is present in ictalurids and many other catfishes as a canal-bearing bone between the supracleithrum and the pterotic, a bone sometimes identified as the extrascapular. The extrascapular is missing in catfishes. Ictalurids have an additional dermal bone above the posttemporal, which is either an independently ossifying fragment of the posttemporal or a neoformation restricted to some members of this family. The single chondral bone of the pectoral girdle originates from a single center of ossification that represents the coracoid. The scapula is missing in catfishes. Dorsal-fin distal radial 2 is absent in catfishes and the foramen of dorsal-fin spine 2 is formed from modifications to the base of the fin-ray itself. Unlike loricarioid catfishes, the urohyal of ictalurids originates solely as an ossification of the sternohyoideus tendons. The anteriormost infraorbital element ossifies from a single center of ossification around the infraorbital sensory canal and represents the lacrimal. The antorbital is missing in catfishes. Finally, skeletal development of I. punctatus is compared to that available for other otophysans, including the cypriniforms Danio rerio and Enteromius holotaenia and the characiform Salminus brasiliensis.

HTML

XML

PDF

]]>
Research Article Fri, 12 Aug 2022 11:38:33 +0300