The planthopper, Nilaparvata lugens Stål (Homoptera: Delphacidae), uses acoustic signals generated by abdominal vibration and transmitted through rice (Oryza sativa L.) plants to locate mates. The influence of temperature (20, 28, and 32°C) on abdominal vibration patterns of individual females and males, proportion of mated females, and responsivity of male to female vibrational signals was investigated. When female and male adults were observed individually, temperatures of 20 and 32°C inhibited abdominal vibration by both genders in terms of proportion of vibrating insects, time spent in vibration per insect, time spent per bout of vibration, or all of these; the effects were more pronounced at 32°C than at 20°C especially in males at 32°C. Although not significantly different, male responsivity to vibrating female was relatively high at 28°C, lower at 32°C, and still lower at 20°C, and finally more males located females at 28°C than at 20°C, which contributes to the higher proportion of mated females at 28°C than at 20 or 32°C. Our results indicate that temperatures of 20 and 32°C inhibit the production of abdominal vibration and, to some extent, reduce male responsivity to female vibrational signals, which may partially explain the frequent population outbreaks in N. lugens in the years with warm autumn.
Marine debris has become a global problem affecting coral health around the globe. However, the photophysiological responses of corals to marine debris stress remain unclear. Therefore, this study firstly investigated transparent and opaque plastic bag shading and fishing nets directly contacting the coral. Photosynthetic performance, pigment content, symbiont density, and calcification rate of a branching coral Pocillopora acuta and a massive coral Porites lutea were investigated after 4 weeks of exposure to marine debris. The results show that the maximum quantum yield of PSII significantly decreased in P. lutea with all treatments, while P. acuta showed no effect on the maximum quantum yield of PSII from any treatments. Transparent plastic bag shading does not affect P. acuta, but significantly affected the maximum photochemical efficiency of P. lutea. Photoacclimation of cellular pigment content was also observed under opaque plastic bag shading for both species at week 2. Fishing nets had the strongest effect and resulted in P. acuta bleaching and P. lutea partial mortality as well as a decline in zooxanthellae density. Calcification rate of P. acuta significantly decreased with treatments using opaque plastic bag and fishing net, but for P. lutea only the treatment with fishing net gave any observable effects. This study suggests that the sensitivities of corals to marine debris differ strongly by species and morphology of the coral.
An unprecedented decline in the diversity and health of coral reefs is occurring around the world as they are threatened by multiple global and local stressors. Rising seawater temperature and low dissolved oxygen (DO) conditions are expected to intensify as a result of climate change. Understanding the responses of corals to these stressors is necessary for making predictions and devising mitigation strategies. The three coral species—Porites lutea, Montipora tuberculosa, and Pocillopora verrucosa—were sampled from Patong Bay, Phuket, Thailand, as representatives of different coral morphologies. Coral nubbins were subjected to experimental investigation under ambient conditions (29 °C, DO > 6 mgL−1), heat stress (32 °C), hypoxia (DO < 2 mgL−1), and heat stress + hypoxia treatments. Photosynthetic performance indicators Fv/Fm and Fv/F0 and physiological parameters Symbiodiniaceae density, pigment concentration, and growth rate were quantified. We found P. verrucosa (branching) to be the most sensitive and severely affected by heat stress or hypoxia, more so than P. lutea (massive) and M. tuberculosa (tabular). The combination of these stressors had less impact on these species, except for a decline in growth rate of M. tuberculosa. This study also suggests that the corals respond differently to high temperature and low oxygen, with their sensitivity depending on species. These responses, however, may differ according to the lighting, especially in hypoxic conditions. The results fill a research gap to help predict the vulnerability of these three coral species in shallow reef habitats under climate change scenarios.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.