ABSTRACT
The age, growth, reproduction and resource development status of Ptychidio jordani, as a critically endangered freshwater fish in the Hongshui River, China, was studied in this work. A total of 525 specimens were collected monthly using the cages and gillnets from October 2021 to September 2022 in the Hongshui River. The scale was used for age determination, and the maximum age for both female and male was estimated to be 5 years and 3 years, respectively. Female and male P. jordani showed different growth patterns, which were expressed as Lt = 261.3 (1-e-0.4885(t-0.1476) ) and Lt = 251.2 (1-e-0.4758(t+0.9643) ), respectively. The overall sex ratio was 1:0.47 (female:male). Female attained sex maturity at 2.34 years (192 mm body length). Month variation of the gonad somatic index indicated that the spawning period occurred from April to October. The absolute fecundity was estimated at 9046 ± 3434 eggs per individual, and the relative fecundity was 38.08 ± 15.77 eggs per gram. The exploitation rate of female and male was 0.233 and 0.495, which indicated that P. jordani was not overfishing. This study provided data on the key life-history traits of P. jordani, which has not been known previously and is essential for conservation strategy and policy development.
Subject(s)
Reproduction , Rivers , Female , Male , Animals , Fertility , Fresh Water , Fishes , SeasonsABSTRACT
A new species, Neodontobutis lani (Odontobutidae) is described from the Zuojiang River, a tributary of the Xijiang River of the Pearl River basin, at Longzhou Town, Guangxi Zhuang Autonomous Region, Southern China. This species can be distinguished from other Neodontobutis species by following characters: anterior head flat, with interorbital width / eye diameter = 1.41.9 (vs. less than 1.4); several rows (vs. single row) of transforming ctenii on posterior edges of body scales; sensory papilla on lower jaw arranged in two oblong clusters (vs. two single lines). It can be distinguished from Odontobutis species by: separated right and left gill membrane (vs. joined); barbel-like projection present on sensory papillae. Molecular phylogenetic analysis of 2,076 nuclear coding loci indicates that N. lani is a sister species of N. hainanensis, the only Neodontobutis species that has been described from China.
Subject(s)
Perciformes , Animals , Cell Nucleus , China , Phylogeny , RiversABSTRACT
A new cave-dwelling fish species Triplophysa guizhouensis is described based on specimens collected from Guizhou, China, in a subterranean system interconnected with the Hongshui River drainage. The species can be distinguished from its congeners by a combination of characters: eyes present; caudal fin with 14 branched rays; inner gill rakers of first gill arch 8-10; posterior chamber of air bladder developed; and body posterior of dorsal fin scaled. A key to species of Triplophysa in the Pearl River basin is provided.
Subject(s)
Caves , Cypriniformes/classification , Air Sacs , Animals , Biodiversity , China , Cypriniformes/anatomy & histology , Eye , Gills , Pigmentation , RiversABSTRACT
In this study, we report the complete mitochondrial genome of Sinocyclocheilus ronganensis. The whole mitochondrial genome is 16,587 bp with an accession number KX778473, and consists of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs genes, and a 936 bp control region. Phylogenetic analysis shows that S. ronganensis is close to cave-restricted S. anophthalmus and surface-dwelling S. grahami. The complete mitogenome of S. ronganensis may provide useful information for studying the genetic mechanism of cavefish, and enrich the fish mitochondrial genome resource for further research.
