Artificial propagation, embryonic development and early larval growth of Triplophysa strauchii.
This study establishes a systematic artificial propagation system for Triplophysa strauchii, reporting an average hatching rate of 87.32% ± 2.16% at 19 ± 1°C.
Where it sits
this study against the rest of the leuprorelin corpusSummary and findings
This study investigates the artificial propagation, embryonic development, and early larval growth of the fish species Triplophysa strauchii. Fertilized eggs were obtained using a combined injection protocol at a water temperature of (19 ± 1)°C. The average hatching rate was reported as 87.32% ± 2.16% within 82 hours.
Abstract
Triplophysa strauchii is an endemic fish species distributed in the plateau cold-water systems of the arid northwest region of China, playing an important ecological role in maintaining the stability of regional aquatic ecosystems. In recent years, due to human activities and habitat degradation, its wild population has been continuously declining, necessitating urgent research on artificial propagation and early development. In this study, wild mature T. strauchii from Sayram Lake were used to systematically investigate artificial propagation, embryonic development and early larval growth. Fertilized eggs were obtained using a combined domperidone (DOM) and luteinizing hormone-releasing hormone analogue (LHRH-A<sub>2</sub>) injection protocol (8 mg/kg + 18 μg/kg for females, half dosage for males) at a water temperature of (19 ± 1)°C. The embryonic development process and larval growth from 0 to 15 days post-hatching (dph) were continuously observed. The results showed that: (1) At a constant water temperature of (19 ± 1)°C, fertilized eggs completed hatching within 82 h, with an average hatching rate of 87.32% ± 2.16%. Embryonic development was divided into 8 stages comprising 29 developmental periods, with a total accumulated temperature of 1573.27°C ·h. By prolonging the cleavage stage (18.4%) and organogenesis stage (37.4%), the integrity and accuracy of organ differentiation under low-temperature conditions were ensured. (2) Yolk sac absorption from 0 to 7 dph exhibited a biphasic pattern (fast-slow) and was completely absorbed by 7 days, marking the transition to exogenous nutrition. Quadratic polynomial regression models for total length, body length, head length and interorbital width against dph showed excellent fit (R<sup>2</sup> >0.984), with growth rate gradually slowing with age. The relatively stable growth of head length and interorbital width reflects an adaptive strategy prioritizing the development of sensory and feeding organs. This study is the first to systematically establish an artificial propagation system for T. strauchii, clarify the timing of embryonic development and the patterns of larval growth, and fill the research gap in artificial propagation and early development of this species, providing a scientific basis and technical support for germplasm conservation, wild population restoration and large-scale artificial breeding of T. strauchii.
Background
The study addresses the ecological importance of Triplophysa strauchii, an endemic fish species in China's plateau cold-water systems, which is facing population decline due to habitat degradation. Previous research has highlighted the need for artificial propagation techniques to support conservation efforts. This study aims to fill the research gap regarding the early developmental stages of this species.
Methods
The study utilized wild mature T. strauchii from Sayram Lake, employing a combined injection protocol of domperidone and luteinizing hormone-releasing hormone analogue at dosages of 8 mg/kg and 18 μg/kg for females, respectively, with half the dosage for males. The embryonic development and larval growth were observed from 0 to 15 days post-hatching, with primary outcomes focused on hatching rates and growth metrics.
Results
The primary endpoint reported an average hatching rate of 87.32% ± 2.16% at a constant water temperature of (19 ± 1)°C, with hatching completed within 82 hours. The embryonic development was categorized into 8 stages and 29 periods, requiring a total accumulated temperature of 1573.27°C·h. Yolk sac absorption occurred from 0 to 7 days post-hatching, with complete absorption marking the transition to exogenous nutrition.
Interpretation
The findings provide a systematic approach to artificial propagation for T. strauchii, establishing critical timelines for embryonic development and larval growth. While the statistical significance of the hatching rate is noted, the clinical relevance for conservation practices remains to be established. Limitations include the lack of detailed population metrics and potential confounding factors related to environmental conditions.
Key findings
- Average hatching rate of 87.32% ± 2.16% at 19 ± 1°C, n=Not reported in abstract.
- Fertilized eggs completed hatching within 82 hours.
- Total accumulated temperature for embryonic development was 1573.27°C·h.
- Yolk sac absorption was completed by 7 days post-hatching.
- Quadratic polynomial regression models for growth metrics showed R² > 0.984.
Limitations
- Not reported in abstract.
- Small sample size not specified.
- Single-site study may limit generalizability.
- Short follow-up period of 15 days post-hatching.