Scholarlink

<p>The African catfish, <i>Clarias gariepinus</i>, is an air-breathing fish that possesses well-developed gills and a specialised air-breathing organ composed of supra-branchial chambers with arborescent organs. The different types of air-breathing behaviours exhibited by <i>C. gariepinus</i> were documented, and air-breathing frequency (<i>f</i><sub>AB</sub>) was assessed in a series of trials where individual <i>C. gariepinus</i> (average mass: 300&#xa0;g; <i>n</i> = 60) were subjected to either avian predation threats, changes in water turbulence and flow, water depth, or environmental noise. Diurnal changes in <i>f</i><sub>AB</sub> were also monitored. Three distinct air-breathing behaviours were observed, distinguishable by the pattern of bubble release through the opercular slits or from the buccal cavity during the ascent to perform air-breathing. Photoperiod clearly modulated <i>f</i><sub>AB</sub> in <i>C. gariepinus</i>, as nocturnal <i>f</i><sub>AB</sub> was almost twice as high as daytime <i>f</i><sub>AB</sub>. Water depth (27, 54, and 81&#xa0;cm) had a significant effect on <i>f</i><sub>AB</sub> (<i>p</i> = 0.021), with <i>f</i><sub>AB</sub> being inversely proportional to water depth. Similarly, flow velocity and turbulence had significant effects on <i>f</i><sub>AB</sub>. Under low turbulence conditions, <i>C. gariepinus</i> performed 1.65 ± 0.18 air-breaths min<sup>−1</sup>, which was 2.3 times higher than <i>f</i><sub>AB</sub> in water without turbulence. In the presence of an avian predator, <i>f</i><sub>AB</sub> was nearly halved and significantly reduced compared to when the predator was absent. While the concentrations of dissolved gases are known to be the main drivers of air-breathing in many air-breathing fish species, including <i>C. gariepinus</i>, the data generated from this study highlight the sensitivity of the species to hydrodynamic alterations and aerial predation threats.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Air-breathing responses of the African catfish (Clarias gariepinus) to experimental hydrodynamics, predation threat, and acoustic stimuli

  • 期刊论文

  • 发表日期：

    2025年6月23日

查看全文
  • Kwasi Adu Obirikorang,
  • Khadijah Yussif,
  • Henry Owusu Adjei,
  • Robert Yadama Laar,
  • Jedida Osei Bediako,
  • Kelvin Fafanyo,
  • Jesslyn Akrokoh,
  • Harriya Musah-Yussif,
  • Priscilla Keziah Viku,
  • Mighty Adanu Atobrah-Dzebu,
  • Peter Vilhelm Skov

摘要

The African catfish, Clarias gariepinus, is an air-breathing fish that possesses well-developed gills and a specialised air-breathing organ composed of supra-branchial chambers with arborescent organs. The different types of air-breathing behaviours exhibited by C. gariepinus were documented, and air-breathing frequency (fAB) was assessed in a series of trials where individual C. gariepinus (average mass: 300 g; n = 60) were subjected to either avian predation threats, changes in water turbulence and flow, water depth, or environmental noise. Diurnal changes in fAB were also monitored. Three distinct air-breathing behaviours were observed, distinguishable by the pattern of bubble release through the opercular slits or from the buccal cavity during the ascent to perform air-breathing. Photoperiod clearly modulated fAB in C. gariepinus, as nocturnal fAB was almost twice as high as daytime fAB. Water depth (27, 54, and 81 cm) had a significant effect on fAB (p = 0.021), with fAB being inversely proportional to water depth. Similarly, flow velocity and turbulence had significant effects on fAB. Under low turbulence conditions, C. gariepinus performed 1.65 ± 0.18 air-breaths min−1, which was 2.3 times higher than fAB in water without turbulence. In the presence of an avian predator, fAB was nearly halved and significantly reduced compared to when the predator was absent. While the concentrations of dissolved gases are known to be the main drivers of air-breathing in many air-breathing fish species, including C. gariepinus, the data generated from this study highlight the sensitivity of the species to hydrodynamic alterations and aerial predation threats.