Aquatic Ecology最新文献

Energy acquisition and allocation between the somatic compartments are essential for the ecological success of an organism. The seasonal pattern of energy allocation among the different organs was evaluated in the snail Zidona dufresnei. The somatic indexes, energy density and energy content of the gonads, digestive gland, foot, and secondary sexual glands of Z. dusfresnei. The lowest foot index (FI), energy density and energy content were found in winter. The high digestive gland index (DI) and energy content (EC_DIG) observed in spring likely coincide with the peak of productivity. The male’s gonads did not show seasonal energetic variation, although the gonadosomatic index (GI) of males was lower in summer than in other months. The mass and energy content of the albumen and capsule glands exhibited a decreasing pattern from spring to winter. The foot is suggested as the main energy reservoir in Z. dufresnei, the digestive gland as an energy reservoir that contributes to the gonadal maturation, whereas the energy of the capsule and the albumen glands contributes to the spawning. This study highlights seasonal variations in the energy content of the foot (edible compartment) and the significance of secondary sexual glands in understanding the bioenergetics of Z. dusfresnei and offspring fitness. These findings should be taken into consideration in fisheries management decisions for this ecologically and commercially important species.

Fresh water fishes carry heavy infection of helminth parasites. Infection of these parasites may result poor growth, postpone sexual maturity and mortality of fishes, and cause human and animal diseases. This study recorded seasonal variations in gastrointestinal parasites found in fishes collected from the Mundeswari River, Hooghly, West Bengal, India. Total 1368 fishes were examined in four different seasons, namely Winter (December, January, February), Summer (March, April, May), Monsoon (June, July, August), Post monsoon (September, October, November) during December 2017–November 2021. Season wise abundance of four types of endo-helminthes namely Acanthocephala, Nematode, Trematode and Cestode, were recorded. The results indicated that climatic conditions are directly or indirectly influenced the intensity of parasitic infection and among the seasons the intestines or body cavity of fishes were recorded high parasitic infection during the winter season as compared to summer, monsoon and post monsoon.

This investigation presents pioneering discoveries concerning the endemic seaweed Ulva ovata across multiple sites in the Gulf of Khambhat, India, going beyond its type locality, Gopnath. The primary objective of this research was to examine the substrate type and various environmental factors affecting seaweed diversity at five sites where endemic U. ovata was found. Identifying 11 seaweed species under Chlorophyta and Rhodophyta phyla, the study highlights rocky sites exhibiting higher Simpson (D) and Shannon (H′) diversity indices, species richness, and percentage cover during cold months. k-dominance analysis indicates more species at Pingaleshwar, Unchakotda, and Gopnath. Bray Curtis similarity shows similarity in seaweed composition between Unchakotda-Pingaleshwar, and Kuda-Khadsaliya, whereas Gopnath forms a different cluster mode. Key species U. rigida and U. ovata, identified by SIMPER analysis, act as bio-indicators for future studies. Five sites demonstrate distinct seawater temperature, dissolved oxygen, light intensity, salinity, total dissolved solids (TDS), electrical conductivity (EC), wind velocity, UV index, nitrate (NO₃⁻), and nitrite (NO₂⁻) significantly impacting seaweed diversity. This study enhances understanding of seaweed distribution and environmental influences in the Gulf of Khambhat, offering insights into ecological dynamics and implications for marine conservation and management strategies.

Commercial success of a pet species predicts its invasiveness, making the most traded species more likely to become introduced. Turtles are among the most traded species, making it critical to monitor their introduction, and in Portugal several invasive turtle species have been detected in nature. This study reports the first official record of Mauremys sinensis and lists its unofficial records in Portugal. This is a critically endangered species in its native range but invasive out of its native range. Two M. sinensis individuals (one adult male and a juvenile) were found in a lake near Évora, alongside native Mauremys leprosa. Additionally, iNaturalist database analysis revealed 14 citizen science records of this species in 10 municipalities in Portugal since 2021 These records were located from North to South of continental Portugal but also in the Madeira Island. The presence of invasive turtles can impact native species through competition, predation, disease transmission, and hybridization. Pet trade is the primary source of these species, and legislation has been ineffective in preventing their introduction. This study also highlights the need for comprehensive strategies, including whitelists and blacklist, to address the invasive pet trade, protect native ecosystems, and prevent further introductions of species like M. sinensis.

Diverse microbial communities play a crucial role in maintaining the proper functioning of river ecosystems and are considered important indicators of river water quality. Although the Seine River being heavily impacted by human activities, little is known about the microbial communities in its surface waters. In order to monitor water quality and promote sustainable use, we studied its microbial diversity using high-throughput sequencing technology, and explored their relationships with physico-chemical properties. The dominant phyla identified were Proteobacteria, Actinobacteriota, Bacteriodota, and Cyanobacteria. The presence of the Alphaproteobacteria and Gammaproteobacteria indicates that the Seine River water nutrient profile is mainly determined by the recalcitrant organic compounds present in WWTP effluents. Bacterial diversity showed significant temporal variability with a highly significant difference in bacterial composition between 2020 and 2021, probably due to variations in water flow favoring Cyanobacteria growth. Summer displayed higher microbial activity and abundance than autumn, attributed to temperature and orthophosphate content. Spatial variation in bacterial composition was observed between sites upstream and downstream of Paris, as well as before and after of the Seine Valenton-WWTP, subject to an accumulation phenomenon and impacted by wastewater treatment. Further assessment of emerging contaminants and other pollutants is required to better understand these variations. These results provide a basic understanding of the microbial community in the Seine River, serving as a reference for assessing the impact of implementing new wastewater disinfection techniques in the near future.

Graphical abstract

The study provides significant insights into the community structure, species diversity and the environmental factors affecting the diversity of MPB in the tropical estuarine habitat of the Cochin estuary. A significant outcome of the present study was the taxonomic identification of 59 species of MPB belonging to 22 genera, which comprised 49 species of diatoms, one species of dinoflagellate, six species of cyanobacteria, two species of euglenophytes and one species of chlorophyte. Major MPB identified in the study were Navicula erifuga, Gyrosigma wansbeckii, Navicula flanatica, Nitzschia sigma, Nitzschia fluminensis, Amphora cymbifera, Nitzschia clausii, Nitzschia lorenziana, Navicula arenaria and Gyrosigma balticum. Principal component analysis indicated that the porewater salinity, sediment temperature, sediment pH, dissolved oxygen (DO), C:N ratio, porewater silicate and sediment chlorophyll a were positively correlated with the diversity of MPB. The intensity of rainfall, OC%, C:S ratio, and TN% were negatively correlated with the diversity of MPB. The study provides a detailed taxonomic inventory of MPB diversity and environmental influences, offering additional insights into tropical estuarine ecology.

Parasites are facing a loss in biodiversity in a changing climate. In this context, the present study aimed to evaluate the influence of climate change on Hoplias malabaricus and its species of monogenetic and digenetic parasites. The models were developed for South America and the species occurrence data were obtained from databases and digital platforms. The bioclimatic, edaphic, elevation, and slope variables were obtained from specialized platforms. Thus, to generate species distribution models, Support Vector Machine, Random Forest and Generalized Linear Model algorithms were used. All predictions of the model for a species were combined to obtain its final model (Ensemble) for the present and future scenarios. As a result, definitive hosts of the parasites showed high climatic suitability. The broad niche of these species indicated that these organisms can show certain opportunistic and generalist characteristics. Unlike their parasites that revealed a more restricted distribution than their host. Also, in a future scenario, endoparasite species will generally reduce 99% of their populations, ectoparasites 93%, while some hosts will increase their populations. In conclusion, the study assumed that future climatic events can influence parasites and their hosts differently, whereas anthropization can influence parasite extinction even without directly affecting their hosts.

Sediments, waters and vegetation work together and cooperate mutually to maintain normal function of mangrove wetland ecosystem. To gained a comprehensive understanding of the response strategies existed by the leaf traits of Aegiceras corniculatum and to identity the key factors that drive leaf traits variation in the response to shrimp aquaculture wastewater, we sampled leaves of A. corniculatum, sediments and interstitial water from non-discharge area (CK), direct discharge area (DDA) and landfill restoration area (LRA) in Qinzhou Bay in southeast coast of China. We established a correlation between leaf vein traits and stomatal traits and abiotic conditions such as pH, nutrient content in sediment. In comparison to CK and LRA, leaf vein traits (primary vein diameter, secondary vein diameter, tertiary vein diameter, enclosed circular area, vein spacing, and tertiary vein density) exhibited a decrease in DDA. This observation suggests that the persistent discharge of shrimp aquaculture wastewater exerts a detrimental impact on the leaves’ mechanical support, nutrient, and water transport capacity. Furthermore, a marked negative correction emerges between stomatal density and length. In contrast, within LRA, an increase in stomatal density and a corresponding reduction in stomatal length indicate a heightened transpiration function of the leaves, thereby enhancing the efficiency of water and inorganic salt transport. Subsequently, the leaf vein traits in LRA are observed to be higher than in CK, suggesting that the leaf traits of A. corniculatum has undergone pre-adaptation to DDA and possesses high phenotypic plasticity. Through the analysis of leaf vein and stomatal traits in diverse shrimp aquaculture wastewater discharge habitats, this study demonstrates that such pre-adaptation and elevated phenotypic plasticity facilitates the adaptation of A. corniculatum to the challenging shrimp aquaculture wastewater environment.

Malacostracans are significant in several environmental processes, making them a major biotic component in aquatic ecosystems. An investigation on the spatio-temporal variations in the diversity and abundance of malacostraca was carried out in the Kallada River for a period of two years from 2019 to 2021. The malacostracan community was represented by 35 species in 17 families and 4 orders during the investigation period. Decapods (24 species), amphipods (7 species), isopods, and tanaids (2 species each) were identified from the Kallada River. Seasonally, PoM (Post-monsoon) witnessed the presence of 33 species closely followed by PrM (Pre-monsoon) and MoN (Monsoon) with 32 species each. The amphipod species Melita zeylanica belonging to the family Melitidae dominated in terms of abundance throughout the study period. Diversity, richness, and dominance indices were increased from the upstream to downstream sites. Contrarily, the highest values of evenness were recorded the upstream and lowest recorded downstream. Diversity analysis values were maximum at downstream sites during the PrM season while the abundance was maximum during the PoM season. Multivariate tools such as CCA (canonical correspondence analysis) and hierarchical clustering were applied to investigate the co-existence of various malacostracan taxa and the relation between the species and water quality parameters. Similar feeding habits and water quality requirements allowed the co-occurrence of malacostracan species. CCA indicates the freshwater and estuarine influences on malacostracan diversity and abundance. The study also assessed the detrimental effects of sewage and municipal effluents on malacostraca at the midstream stations. However, the low diversity at the upstream stations was attributed to the natural environmental conditions.

Sagartaal is located in Budaun with geographical coordinates 28.0512°N and 79.1305°E in Nawada region, Uttar Pradesh, Uttar Pradesh, India. Understanding the composition, diversity, and abundance of the zooplankton is vital for better utilization of such waterbodies. The present study was carried out from October 2022 to September 2023. A total of 24 species belonging to 16 species of Rotifera, 4 species of Cladocera, 2 species of Copepoda, and 2 species of Ostracoda were recorded. The prominent species were Brachionus forficula, B. calyciflourus, Keratella cochlearis, Simocephalus sp., Cyclops sp., and Mesocyclops sp. Zooplankton showed seasonal variations in their species composition, abundance, and diversity concerning water temperature, pH, total alkalinity, dissolved oxygen, and hardness. The zooplankton density was recorded as maximum in winter and minimum in monsoon. Statistically, zooplankton shows significant correlations as Rotifera with EC, BOD (r =− 0.50; − 0.58, respectively); while with total hardness (r = 0.75); Cladocera with DO (r = 0.53), alkalinity (r = 0.57), nitrate (r = 0.56), and phosphate (r = − 0.49). The highest Shannon index (2.83) was obtained for summer, due to the lowest value of the dominance index (0.07) for this season. More studies are warranted on Monitoring such ecosystems as Sagartaal to understand the effects of anthropogenic pressure on zooplankton's community structure, can help in identifying the indicator species to formulate effective conservation planning.