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Tuesday, October 1st, 2024
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| 6:40a | [Ichthyology • 2024] Opsariichthys rubriventris • A New Species of Cyprinid Genus Opsariichthys (Teleostei: Cyprinidae) from the Pearl River, Southern China
Abstract A new cyprinid fish, Opsariichthys rubriventris sp. nov., is described from the Xizhijiang River, a tributary of the Pearl River basin in Huizhou City, Guangdong Province, southern China. The species is distinguished from all other congeners by the following combination of characters: predorsal scales 13–14; lower jaw projecting slightly beyond upper jaw; cheek with two mainly longitudinal rows of tubercles; and lower jaw, belly, pectoral fin, and anterior margin of anal fin in adult males being reddish-orange. The principal component analysis result of the morphological data indicated that O. rubriventris sp. nov. could be clearly distinguished fromfour other congeners. The phylogenetic analysis conducted in this study, utilizing both Maximum Likelihood (ML) and Bayesian Inference (BI) methods, supported the monophyly of the novel species O. rubriventris sp. nov. at the species level. Additionally, the genetic distance analysis revealed that O. rubriventris sp. nov. exhibits a genetic distance ranging from 0.14 to 0.16 with its congeneric species, further affirming its taxonomic status. Keywords: taxonomy; phylogenetic analysis; Guangdong province; opsariichthine
Opsariichthys rubriventris sp. nov. J.-B. Chen, Y.-T. Li, J.-J. Zhou & J.-J. Wang, Diagnosis: Opsariichthys rubriventris sp. nov. can be distinguished from the congeneric species by the following combination of morphological characters: (1) no maxillary barbels; (2) no anterior notch at the tip of the upper lip; (3) lateral line scales 39–43; (4) predorsal scales 13–14; (5) narrow body width; (6) lower jaw protrudes slightly beyond the front of the snout; (7) 2 rows of pearl organs of the cheek, and the pearl organs are cone-shaped; (8) the pectoral fins of adult males do not extend to the origin of the pelvic fins; (9) adult males have significant nuptial coloration; the lower jaw and ventral side are orange-red; (10) the envelope of the first six rays of the anal fin of adult males, females, and juveniles is orange-red, and the remaining rays gradually become colorless. Morphologically, O. rubriventris sp. nov. can be clearly distinguished from its congeners O. bidens and O. hainanesis based on these characteristics: O. bidens and O. hainanesis have a concave notch at the front of the upper jaw in which the anterior end of the mandible fits, while the O. rubriventris sp. nov. does not have a deep notch at the front of the upper jaw ... Etymology: The specific epithet rubriventris is constructed from the Latin words ruber, meaning red, and venter, meaning belly, an adjective, referring to the red belly of the mature males. In addition, since O. rubriventris sp. nov. is only distributed in Guangdong Province, China, we suggest its Chinese vernacular to be “广东马口鱼”. Jia-Bo Chen, Ying-Tao Li, Jia-Jun Zhou, Cheng Li, Guo-Xi Weng, Hung-Du Lin and Jun-Jie Wang. 2024. A New Species of Cyprinid Genus Opsariichthys (Teleostei: Cyprinidae) from the Pearl River, Southern China. Diversity. 16(10), 596. DOI: doi.org/10.3390/d16100596 | ||||||||||||
| 7:35a | [Herpetology • 2024] Adhaerobufo gen. n. • The Remarkable Larval Morphology of Rhaebo nasicus (Werner, 1903) (Anura: Bufonidae) with the Erection of A New bufonid Genus and insights into the Evolution of Suctorial Tadpoles
Abstract Tadpoles serve as crucial evidence for testing systematic and taxonomic hypotheses. Suctorial tadpoles collected in Guyana were initially assigned to Rhaebo nasicus through molecular phylogeny. Subsequent analysis of larval and adult morphological traits revealed synapomorphies within the clade encompassing R. nasicus and R. ceratophrys, prompting the recognition of a new genus described herein as Adhaerobufo. The new genus is distinguished from other bufonids by specific phenotypic traits including an enlarged, suctorial oral disc with distinct papillae arrangements, and the presence of certain muscles and narial vacuities at the larval stage. However, only a few adult external characteristics (e.g., enlarged eyelids, infraocular cream spot), seem to be reliably discriminative from related genera. This study underscores the significance of larval morphology in anuran systematics and offers new insights into the evolution of suctorial and gastromyzophorous larvae within bufonids. Keywords: Evolution, Larval traits, Musculoskeletal system, Pantepui, Suctoriality, Systematics, Taxonomy
Adhaerobufo gen. nov. Type species: Bufo nasicus (Werner, 1903) comb. nov. Content: Adhaerobufo ceratophrys (Boulenger, 1882) comb. nov., and Adhaerobufo nasicus (Werner, 1903) comb. nov. Etymology: Adhaerobufo gen. nov. (gender masculine) is derived from the Latin adhaerens, meaning adherent and the Latin būfo, meaning toad. The name refers to the unique suctorial morphology of their tadpoles. Definition and diagnosis: Adhaerobufo gen. nov. can be differentiated from all other Bufonidae by the combination of the following characters: (1) tadpole with enlarged, suctorial, oral disc; (2) tadpole oral disc with a complete row of marginal papillae; (3) tadpole oral disc with multiple rows of submarginal papillae on the lower lip and by a single row of marginal papillae on the upper lip; (4) tadpole oral disc with an uninterrupted second anterior row of keratodonts; (5) presence of the m. interhyoideus posterior at larval stage; (6) presence of the m. rectus abdominis anterior at larval stage; (7) presence of narial vacuities in the buccopharyngeal cavity at larval stage; (8) projecting, enlarged eyelid in adults; (9) presence of an infraocular cream spot in adults, (10) sphenethmoid relatively narrow, overlapping only the medial ends of the palatines; and (11) posterior process of the prootic prominent and notched.
Pedro Henrique dos Santos Dias, Jackson R. Phillips, Martín O. Pereyra, D. Bruce Means, Alexander Haas and Philippe J. R. Kok. 2024. The Remarkable Larval Morphology of Rhaebo nasicus (Werner, 1903) (Amphibia: Anura: Bufonidae) with the Erection of A New bufonid Genus and insights into the Evolution of Suctorial Tadpoles. Zoological Letters. 10: 17. DOI: doi.org/10.1186/s40851-024-00241-0  |
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