Nitrogen excretion and oxygen consumption under severe hypoxia in siluriform fishes from the Amazon.

IF 1.7 3区 农林科学 Q2 FISHERIES
Bernd Pelster, Chris M Wood, Adalberto Luis Val
{"title":"Nitrogen excretion and oxygen consumption under severe hypoxia in siluriform fishes from the Amazon.","authors":"Bernd Pelster, Chris M Wood, Adalberto Luis Val","doi":"10.1111/jfb.70022","DOIUrl":null,"url":null,"abstract":"<p><p>Siluriform fishes collected from the Rio Negro and Rio Solimões proved to be highly resistant to aquatic hypoxia. In all four species analysed in this study, aquatic oxygen consumption significantly decreased from normoxic levels at water PO<sub>2</sub> values near 1 kPa. Air-breathing activity was observed only in Sturisoma sp. (Rio Negro). In this species, under severe hypoxia, oxygen uptake from the air dominated, but total oxygen uptake was significantly lower than that under normoxic conditions. In Anadoras weddellii (Rio Solimões), aquatic surface respiration was detected. However, the other species (Tympanopleura atronasus and three members of the family of Sternopygidae; Rio Solimões) showed no attempt to supplement aquatic oxygen uptake, even under severe hypoxia. In all species tested, neither ammonia nor urea-N excretion was affected by the decreasing water PO<sub>2</sub>. At the lowest water PO<sub>2</sub> levels, the reduction in total oxygen uptake in the face of unchanged nitrogenous waste excretion resulted in extraordinary high nitrogen quotient (NQ) ratios. In normoxia, NQ ratios ranged from 0.16 to 0.34. Urea-N excretion contributed between 19% and 28% to total nitrogen excretion and appeared to be unrelated to natural diet as indicated by the gut length-to-fork length ratio or to plasma urea-N levels. Overall, our data underline the quantitative importance of urea-N for nitrogen excretion in siluriform fishes.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7000,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of fish biology","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1111/jfb.70022","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"FISHERIES","Score":null,"Total":0}
引用次数: 0

Abstract

Siluriform fishes collected from the Rio Negro and Rio Solimões proved to be highly resistant to aquatic hypoxia. In all four species analysed in this study, aquatic oxygen consumption significantly decreased from normoxic levels at water PO2 values near 1 kPa. Air-breathing activity was observed only in Sturisoma sp. (Rio Negro). In this species, under severe hypoxia, oxygen uptake from the air dominated, but total oxygen uptake was significantly lower than that under normoxic conditions. In Anadoras weddellii (Rio Solimões), aquatic surface respiration was detected. However, the other species (Tympanopleura atronasus and three members of the family of Sternopygidae; Rio Solimões) showed no attempt to supplement aquatic oxygen uptake, even under severe hypoxia. In all species tested, neither ammonia nor urea-N excretion was affected by the decreasing water PO2. At the lowest water PO2 levels, the reduction in total oxygen uptake in the face of unchanged nitrogenous waste excretion resulted in extraordinary high nitrogen quotient (NQ) ratios. In normoxia, NQ ratios ranged from 0.16 to 0.34. Urea-N excretion contributed between 19% and 28% to total nitrogen excretion and appeared to be unrelated to natural diet as indicated by the gut length-to-fork length ratio or to plasma urea-N levels. Overall, our data underline the quantitative importance of urea-N for nitrogen excretion in siluriform fishes.

亚马逊河志卢形鱼类在严重缺氧条件下的氮排泄和氧消耗。
从里约热内卢Negro和里约热内卢Solimões采集的志卢形鱼被证明对水中缺氧具有高度的抵抗力。在本研究分析的所有四种物种中,水体PO2值接近1千帕时,水生耗氧量显著下降。仅在Sturisoma sp. (b里约热内卢Negro)中观察到空气呼吸活动。在严重缺氧条件下,该物种主要从空气中吸氧,但总吸氧量明显低于常氧条件下。在Anadoras weddellii(里约热内卢Solimões)检测到水生表面呼吸。然而,其他种(鼓膜和胸骨蝶科的三个成员);里约热内卢Solimões)显示,即使在严重缺氧的情况下,也没有尝试补充水生氧气的摄取。在所有被试物种中,氨氮和尿素氮的排泄均不受水体PO2下降的影响。在最低PO2水平下,面对不变的含氮废物排泄,总摄氧量的减少导致氮商(NQ)比率异常高。在常氧条件下,NQ比值为0.16 ~ 0.34。尿素- n排泄占总氮排泄的19% - 28%,从肠道长度与叉长比或血浆尿素- n水平来看,似乎与天然饮食无关。总的来说,我们的数据强调了尿素- n对志卢形鱼类氮排泄的定量重要性。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Journal of fish biology
Journal of fish biology 生物-海洋与淡水生物学
CiteScore
4.00
自引率
10.00%
发文量
292
审稿时长
3 months
期刊介绍: The Journal of Fish Biology is a leading international journal for scientists engaged in all aspects of fishes and fisheries research, both fresh water and marine. The journal publishes high-quality papers relevant to the central theme of fish biology and aims to bring together under one cover an overall picture of the research in progress and to provide international communication among researchers in many disciplines with a common interest in the biology of fish.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信