scholarly journals The Effect of Different Habitat Types and Ontogenetic Stages on the Diet Shift of a Critically Endangered Fish Species, Coreius guichenoti (Sauvage and Dabry de Thiersant, 1874)

2018 ◽  
Vol 15 (10) ◽  
pp. 2240 ◽  
Author(s):  
Zhi Yang ◽  
Xiaojuan Chen ◽  
Na Zhao ◽  
Huiyuan Tang ◽  
Jiangping Tao ◽  
...  
Keyword(s):  
Fish Species ◽  
Critically Endangered ◽  
Food Sources ◽  
Three Gorges Reservoir Area ◽  
Diet Shift ◽  
Isotopic Niche ◽  
Spawning Ground ◽  
Habitat Types ◽  
Endangered Fish ◽  
Ontogenetic Stages

This study examined the effect of habitat types and ontogenetic stages on the diet shift of Coreius guichenoti (Sauvage and Dabry de Thiersant, 1874), a critically endangered fish species. Based on the stable isotope analysis method, the following was explored: the variations in δ13C and δ15N values, isotopic niche width and four basal food sources (Mollusks, Macrocrustaceans, Aquatic insect larvae and particulate organic matters (POMs)) among three essential habitat types (the spawning ground, natural riverine feeding and nursery area, and Three Gorges Reservoir area) and between two ontogenetic stages (immature and fully mature stages). A diet shift associated with habitat type changes was observed, but there were no obvious differences in diet composition between the two ontogenetic stages. Dietary plasticity and a preference for specific foods were the important determinants of feeding behavior through the life history of this species. POM was important for the survival of this species in the resource-limited spawning ground, but this species fed more heavily on higher-order consumers in resource-abundant areas. This study highlights the importance of maintaining free connectivity among different habitats (particularly spawning grounds) to ensure the long-term sustainability of potamodromous fish species as well as the full investigation of all types of critical habitats for understanding the trophic ecology of a single fish species.

scholarly journals Habitat use by two extremophile, highly endemic, and critically endangered fish species (Gambusia eurystoma and Poecilia sulphuraria ; Poeciliidae)

2016 ◽  
Vol 26 (6) ◽  
pp. 1155-1167 ◽  
Author(s):  
Zachary W. Culumber ◽  
Garrett W. Hopper ◽  
Nicholas Barts ◽  
Courtney N. Passow ◽  
Samuel Morgan ◽  
...  
Keyword(s):  
Habitat Use ◽  
Fish Species ◽  
Critically Endangered ◽  
Endangered Fish

Integrating Hydroacoustic and Optical Video Technologies to Identify the Riverbed Substrate at the Spawning Reach of Chinese Sturgeon

2014 ◽  
Vol 955-959 ◽  
pp. 1235-1240 ◽  
Author(s):  
Hui Zhang ◽  
Cheng You Wang ◽  
Hao Du ◽  
Jin Ming Wu ◽  
Li Shen ◽  
...  
Keyword(s):  
Fish Species ◽  
Site Selection ◽  
Critically Endangered ◽  
Chinese Sturgeon ◽  
Endangered Fish ◽  
Acoustic Backscattering ◽  
Spawning Site ◽  
The Relationship ◽  
Medium Diameter ◽  
Selection Of

Riverbed substrate is important to many riverine organisms, however, it is normally difficult to study the substrate intensively especially in large and fast flowing rivers. The Chinese sturgeon Acipenser sinensis is a critically endangered fish species, it spawns on a specific riverbed substrate. In this paper, the hydroacoustic and underwater optical video technologies were integrated to study the riverbed substrate at the only remaining spawning area of the fish. Sixteen samples were firstly studied to verify the relationship between acoustic backscattering characteristics (hardness and roughness) and video observed characteristics (embeddedness and medium diameter of the grain). Then eight vertical mobile hydroacoustic surveys were conducted to acoustically map the 16 km spawning reach. The results revealed that the heterogeneous mix of boulder/cobble and sand was the dominant substrate at the spawning reach. However, the embeddedness and medium diameter of the grain varied within the area which tend to affect the spawning site selection of the fish. This study indicated that the combination of hydroacoustic and optical video technologies could be very useful to study the riverbed substrate in river ecological issues.

scholarly journals Assessment of instream structures for habitat improvement for two critically endangered fish species

2010 ◽  
Vol 45 (1) ◽  
pp. 113-124 ◽  
Author(s):  
I. Boavida ◽  
J. M. Santos ◽  
R. V. Cortes ◽  
A. N. Pinheiro ◽  
M. T. Ferreira
Keyword(s):  
Fish Species ◽  
Critically Endangered ◽  
Endangered Fish ◽  
Habitat Improvement

Jenis-Jenis Ikan Indonesia yang Kritis dan Terancam Punah

2021 ◽  
Vol 10 (1) ◽  
pp. 53-59
Author(s):  
Andri Iskandar ◽  
M Muslim ◽  
Andri Hendriana ◽  
W Wiyoto
Keyword(s):  
Foreign Language ◽  
Fish Species ◽  
Critically Endangered ◽  
Literature Study ◽  
Endangered Fish ◽  
The Public ◽  
Critically Endangered Species ◽  
The Status ◽  
In The Wild ◽  
Rule Out

ABSTRACTIndonesia has a high diversity of fish species. Some fish species are critical and endangered. Information on Indonesian native and endemic fish species needs to be disseminated to the public. Such information is available in various sources and is generally in a foreign language. Therefore, the purpose of this research is to inventory and distribute information about several species of fish native to Indonesian public waters that need special attention because they are endangered and critically endangered. Species of fish, especially species that have been critically endangered, do not rule out turning into extinct in the wild (extinct in the wild). The decline in the status of the above from vulnerable (vulnerable) to endangered (endangered) and critical (critically endangered) or even become extinct in the wild (extinct in the wild) caused by various factors, including the existence of fisheries activities that tend to exploit natural resources without offset by conservation activities and increasing pollution of water conditions. With this information, it is expected to anticipate the extinction of these species. The study was conducted using the literature study method. Based on the search results, there were 22 endangered fish species and 15 critically endangered fish species. The Indonesian government has designated 20 protected fish species. Domestication of endangered and critical species is urgent to do, to prevent the extinction of these species. ABSTRAKIndonesia memiliki keanekaragaman spesies ikan yang tinggi. Beberapa spesies ikan sudah kritis dan terancam punah. Informasi jenis-jenis ikan asli dan endemik Indonesia perlu diserbarluaskan ke masyarakat. Informasi tersebut terdapat diberbagai sumber dan umumnya berbahasa asing. Oleh karena itu, tujuan penelitian ini adalah untuk menginventarisasi dan mendistribusikan informasi tentang beberapa spesies ikan asli penghuni perairan umum Indonesia yang perlu mendapat perhatian khusus karena berstatus terancam punah (endangered) dan kritis (critically endangered). Spesies-spesies ikan tersebut terutama spesies yang sudah berstatus kritis terancam punah, tidak menutup kemungkinan berubah menjadi punah di alam liar (extinct in the wild). Terjadinya penurunan status diatas dari rentan (vulnerable) ke terancam punah (endangered) dan kritis (critically endangered) atau bahkan menjadi punah di alam liar (extinctin the wild) disebabkan oleh berbagai macam faktor, diantaranya adanya kegiatan perikanan yang cenderung mengeksploitasi sumber daya alam tanpa diimbangi dengan kegiatan konservasi serta meningkatnya pencemaran terhadap kondisi perairan. Dengan adanya informasi ini diharapkan dapat melakukan antisipasi pencegahan kepunahan spesies tersebut. Penelitian dilakukan dengan metode studi literatur. Berdasarkan hasil penelusuran, diperoleh 22 spesies ikan yang terancam punah (endangered) dan 15 spesies ikan yang sudah kritis (critically endangered). Pemerintah Indonesia telah menetapkan 20 spesies ikan yang dilindungi. Domestikasi spesies-spesies yang terancam punah dan kritis sudah mendesak untuk dilakukan, untuk mencegah kepunahan spesies tersebut. 

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

scholarly journals Plant Succession, Ecological Restoration and the Skinks of Stephens Island / Takapourewa

2021 ◽  
Author(s):  
◽  
Cielle Stephens
Keyword(s):  
Ecological Restoration ◽  
Body Condition ◽  
Plant Succession ◽  
Food Sources ◽  
Habitat Types ◽  
Thermal Range ◽  
Tail Loss ◽  
The North ◽  
Occupancy Rates ◽  
The Impact

Ecological restoration often involves revegetation. I have investigated the impact of revegetation on the distribution, abundance and body condition of skinks on Stephens Island (Takapourewa). I tested the prediction that only one, Oligosoma infrapunctatum, of the four skink species (Oligosoma lineoocellatum, O. nigriplantare polychroma, O. infrapunctatum andO. zelandicum) will benefit in terms of abundance and distribution from revegetation. Stephens Island is a Wildlife Sanctuary in the north-western Marlborough Sounds, New Zealand. The island is known for its diverse and abundant reptile community. Prior to the mid 19th century Stephens Island was covered in forest. Nearly 80% of this forest was destroyed following the establishment of a lighthouse and farm on the island in 1894. In 1989, when the control of Stephens Island passed to the Department of Conservation, reforestation became a key conservation goal. Stephens Island is currently a mosaic of different habitat types from pasture to coastal forest. Pitfall traps caught skinks for a mark-recapture study in four replicated habitat types: forest, tussock, pasture and replanted.<br><br>Oligosoma lineoocellatum comprised 75% of all individuals caught. Densities of O. lineoocellatum were higher in replanted habitat (3020/ha in December and 3770/ha in March) than tussock (2690/ha in December and 2560/ha in March) and lowest in the pasture (1740/hain December and 1960/ha in March). Rates of captures were too low to perform density estimates for the other three species. Trap occupancy rates indicate O. nigriplantare polychroma is more common in the tussock habitat, and O. infrapunctatum is more common in the replanted habitat. Few O. zelandicum were found, primarily in the tussock habitat. Pasture areas replanted 13 years ago (now scrub habitat) support a higher diversity and abundance of skinks. Forest areas remain depauperate of skinks. Skink preference for replanted areas suggests that, for now, revegetation benefits their populations, possibly due to greater food sources, lower predation pressure and a wider thermal range.<br><br>Body condition (log weight/ log snout-vent length) and proportion of tail loss of skinks were similar in the different habitat types. However, both O. nigriplantare polychroma and O.lineoocellatum had higher body condition in the replanted than the tussock habitat. Juvenile skinks had significantly lower body condition and a lower proportion of tail loss. Skink body condition was not negatively affected by revegetation or by different habitats, despite the large differences between the habitats. Revegetation currently benefits skink populations. Maintaining a mosaic of habitat types is recommended, because, should revegetation create more forest habitat through plantations or plant succession, it is likely that the population of all four species of skink will decline.<br>

scholarly journals Microhabitats Affect Population Size and Plant Vigor of Three Critically Endangered Endemic Plants in Southern Sinai Mountains, Egypt

Land ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 86 ◽  
Author(s):  
Amal M. Fakhry ◽  
Ali El-Keblawy ◽  
Hatem A. Shabana ◽  
Ibrahim El Gamal ◽  
Amir Shalouf
Keyword(s):  
Climate Change ◽  
Population Size ◽  
Endemic Species ◽  
Climate Changes ◽  
Small Population ◽  
Critically Endangered ◽  
High Mountains ◽  
Habitat Types ◽  
Growing Seasons ◽  
Steep Slopes

Endemic species on mountains often have narrow altitudinal ranges and are more threatened at the higher altitudes, especially with climate changes. However, plants could use special microhabitats at the mountain tops as proper places for surviving the climate change (i.e., refugia). We assessed population attributes of three critically endangered endemic species (Primula boveana Decne ex Duby, Rosa arabica Crep., and Silene leucophylla Boiss.) in two growing seasons (2006/2007 and 2013/2014), differing in the received rainfalls in microhabitats at the high mountains of southern Sinai. Both P. boveana and S. leucophylla had very small population size, but significantly increased in the 2013/2014 growing season which received above average rainfalls. The population of R. arabica is the smallest (around 40 individuals) and did not increase, even after the increase in rainfalls. Whereas P. boveana is present in fewer sites and grew in small number of specific microhabitats, both S. leucophylla and R. arabica were recorded in most studied sites and habitat types. Unlike R. arabica, both P. boveana and S. leucophylla were recorded in caves and steep slopes and on the top of the mountains. This indicates that these sheltered mist microhabitats are the best for future conservation of these species after climate change.

scholarly journals Freshwater Fish Species of the Oorlogskloof River, Northern Cape Province, South Africa

Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 8-16
Author(s):  
P.P. Ramollo ◽  
M. Schumann ◽  
W.A.J. Pretorius
Keyword(s):  
South Africa ◽  
Freshwater Fish ◽  
Relative Abundance ◽  
Fish Species ◽  
Freshwater Fishes ◽  
Endangered Fish ◽  
Freshwater Fish Species ◽  
Northern Cape

The freshwater fish of Oorlogskloof River were sampled in March 2010. The study aimed to determine the distribution and relative abundance of freshwater fish in the Oorlogskloof River. A total of 4643individuals represented by five fish species belonging to two families were sampled. The Barbus anoplus was only sampled in the upper reaches of the Oorlogskloof River gorge while endangered Labeobarbus capensis appeared downstream in the Oorlogskloof River. Barbus serra dominated the fish species in the system. The invasion of Tilapia sparmanni in this system was confirmed during the survey andthe species appeared to be widespread throughout the system. At this stage it does not appear to be posing a serious threat to the endangered fish species. The Oorlogskloof River can be considered as a potential refuge site for the conservation of some endemic and threatened freshwater fishes of South Africa.DOI: http://dx.doi.org/10.3126/on.v10i1.7746

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