A long-term study on crustacean plankton of a shallow tropical lake: the role of invertebrate predation

Author:

Arcifa Marlene S.,Dos Santos Ferreira Tânia C.,Fileto Claudia,Maioli Castilho-Noll Maria S.,Bunioto Taís C.,Minto Walter J.

Abstract

<p>The primary factor that governs the size and species composition of zooplankton is still a controversial issue and temperature is considered the main factor responsible for latitudinal differences. In waters with a narrow temperature range, such as in the tropics, predation may be a more important factor. Nearly three decades of intermittent studies of the crustacean plankton in a shallow tropical lake revealed that the main event that led to their restructuring was the appearance of a second predator, the water mite <em>Krendowskia </em>sp. The new predator and larvae of the dipteran <em>Chaoborus brasiliensis</em> Theobald exerted a combined, although asymmetrical effect on microcrustaceans. The period when the mite was detected was followed by the restructuring of the crustacean plankton community. Predation by these two invertebrates emerged as the factor responsible for community changes, involving an increased contribution of copepods and decreases in the relative abundance of smaller cladoceran species. In the short term, the mite caused a decrease in species richness and the annual mean instantaneous composition of cladocerans, a predominance of large-sized species (<em>Daphnia ambigua </em>Scourfield<em> </em>and <em>Daphnia gessneri</em> Herbst) and the virtual disappearance of small species (e.g., <em>Bosmina tubicen</em> Brehm). The long-term impact resulted in increased species richness and the dominance of large and medium-sized cladocerans, such as <em>D. gessneri</em> and <em>Ceriodaphnia richardi</em> Sars. The larger body size of three cladocerans, the two <em>Daphnia</em> species and <em>B. tubicen</em>, in the long term, may be a response to the dominant predator, <em>Chaoborus</em>. The seasonal variation in the predator abundance, mainly <em>Chaoborus </em>larvae, allowed the prey to recover during the cool season. The copepods <em>Tropocyclops prasinus meridionalis</em> (Fischer) and <em>Thermocyclops decipiens</em> Kiefer were less affected by predation than the cladocerans; their contribution to the crustacean plankton increased 12-28% after the mite appeared. The top-down effect on crustacean plankton did not affect the phytoplankton, which remained dominated by chlorophyceans and the nanoplankton fraction before and after the zooplankton community restructuring.</p>

Publisher

PAGEPress Publications

Subject

Water Science and Technology,Ecology,Aquatic Science

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3