scholarly journals Spatiotemporal variation in wetland fish assemblages in the Western Ghats region of India

Author(s):  
Archis R. Grubh ◽  
Kirk O. Winemiller

The Western Ghats region of peninsular India contains high diversity of freshwater fishes that support artisanal fisheries, but no studies to date have investigated fish assemblages of the region's extensive wetlands. This study examined fish population densities and the structure of local species assemblages in pools of the Periyakulam wetland of the Western Ghats. From 2000 to 2001, fishes and local abiotic environmental parameters were surveyed during three periods with contrasting rainfall (dry, major wet, minor wet). We hypothesized that fish density would be higher during the dry season when aquatic habitat is reduced, and that local assemblage structure would be strongly associated with habitat conditions. Total fish densities were higher during the dry season, but the magnitude of seasonal change was relatively low, and this apparently was because changes in water depth were minimal due to operation of sluice gates that control wetland hydrology. Chanda nama, Pseudetroplus maculatus, Rasbora daniconius, and Danio aequipinnatus were dominant species in most habitats during all three seasons. Multivariate ordinations revealed strong associations between assemblage structure and habitats based on vegetation cover. Local assemblages in shallow-vegetated habitats varied seasonally in association with gradients of rainfall and water quality parameters. Spatial variation of local fish assemblages in the Periyakulam wetland appears to be maintained by species-specific habitat selection. Although hydrologic regulation probably has reduced seasonal variation in the structure of local assemblages, seasonal differences still occur and appear to be caused by species differences with regard to periods of reproduction, recruitment, dispersal and habitat selection.

2008 ◽  
Vol 59 (2) ◽  
pp. 97 ◽  
Author(s):  
Thomas S. Rayner ◽  
Bradley J. Pusey ◽  
Richard G. Pearson

Strong relationships between seasonal flooding, instream habitat structure and fish assemblages have been well documented in large tropical rivers (e.g. the flood pulse concept). However, the mechanics of these relationships are likely to differ substantially in smaller coastal rivers, such as those in Costa Rica, south-east Brazil and Australia’s Wet Tropics. These systems typically feature steep upland streams with short, deeply incised lowland channels and poorly connected floodplains. This hypothesis was investigated by documenting spatial and temporal variation in fish-habitat relationships in the Mulgrave River, north-east Queensland. Sampling was conducted at four lowland sites under a range of flow conditions, from dry-season baseflows to a one-in-ten-year flood. Longitudinal environmental gradients and fine-scale habitat patches were important in regulating fish assemblage structure during the dry season. However, high wet-season flows, constrained by the deep channel, acted as disturbances rather than gentle flood-pulses. In particular, the mobilisation of bed sediments led to scouring of aquatic vegetation and a dramatic reduction in habitat heterogeneity. Seasonal movements of fish led to significant changes in assemblage structure – from a community dominated by Neosilurus ater, Hypseleotris compressa, Awaous acritosus and Redigobius bikolanus during the dry season, to one dominated by Nematalosa erebi, Ambassis agrammus and Glossamia aprion during the wet season. Based on these observations, together with information from the literature, a conceptual model of fish-habitat dynamics is presented that is better suited to small tropical rivers than those developed in larger systems with expansive floodplains.


2021 ◽  
Vol 13 (13) ◽  
pp. 20033-20055
Author(s):  
Naveen Babu Kanda ◽  
Kurian Ayushi ◽  
Vincy K. Wilson ◽  
Narayanan Ayyappan ◽  
Narayanaswamy Parthasarathy

Documenting the biodiversity of protected areas and reserve forests is important to researchers, academicians and forest departments in their efforts to establish policies to protect regional biodiversity. Shettihalli Wildlife Sanctuary (SWS) is an important protected area located in the central Western Ghats of Karnataka state known for its diverse flora and fauna with distinct ecological features. For the last four decades the sanctuary has witnessed the loss of forest cover, yet the vegetation in few locations is relatively undisturbed. The current inventory was undertaken during 2019–2020 to provide a checklist of woody species from SWS under-researched earlier. The list comprises 269 species of trees, lianas and shrubs distributed in 207 genera and 68 families. The most diverse families are Fabaceae, Moraceae, Rubiaceae, Rutaceae, Lauraceae, Apocynaceae, Meliaceae, Malvaceae, Phyllanthaceae, and Anacardiaceae, representing 48% of total woody flora. The sanctuary shelters 263 native and six exotic plant species. Thirty-nine species were endemic to the Western Ghats, five species to peninsular India and one species to the Western Ghats and Andaman & Nicobar Islands. Four forest types, i.e., dry deciduous, moist deciduous, semi-evergreen, and evergreen forests, are represented in the sanctuary. Of the total species, only seven occurred in all forest types, while 111 species are exclusive to a single forest type. One-hundred-and-four taxa were assessed for the International Union for Conservation of Nature & Natural Resources (IUCN) Red List. Ten species that fall under Near Threatened, Vulnerable, and Endangered categories were encountered occasionally. The baseline data generated on plant diversity will be useful in highlighting the importance of these forests for species conservation and forest management. Such data form a cornerstone for further research. For instance, to understand the effect of invasive species and human impacts on the diversity of the region. 


Zootaxa ◽  
2019 ◽  
Vol 4571 (3) ◽  
pp. 383
Author(s):  
AKSHAY KHANDEKAR

A new species of the gekkonid genus Cnemaspis is described based on a series of nine specimens from near Sankari in Salem district, Tamil Nadu state, southern India. The new species is diagnosable by the following suite of characters: a small-sized Cnemaspis (adult snout to vent length less than 33 mm); heterogeneous dorsal pholidosis consisting of weakly keeled granular scales intermixed with large strongly keeled, conical tubercles, 9–11 rows of dorsal tubercles, 12–17 tubercles in paravertebral rows; spine-like scales absent on flank, 17–20 lamellae under digit IV of pes. Males with 4–6 femoral pores on each thigh, separated on either side by eight poreless scales from four precloacal pores; precloacal pores separated medially by a single poreless scale; two single dorsal ocelli on occiput and between forelimb insertions, two pairs of ocelli on either side just anterior and posterior to forelimb insertions. Cnemaspis agarwali sp. nov. is the fifth endemic species of Cnemaspis from peninsular India outside the Western Ghats and highlights the rich and unique diversity of this understudied region. 


Zootaxa ◽  
2019 ◽  
Vol 4609 (1) ◽  
pp. 68
Author(s):  
AKSHAY KHANDEKAR ◽  
NIKHIL GAITONDE ◽  
ISHAN AGARWAL

We present a preliminary ND2 phylogeny of South Asian Cnemaspis, recovering a number of deeply divergent clades within Indian Cnemaspis, endemic to the southern and northern Western Ghats besides the Mysore Plateau and hills of Tamil Nadu. There are a number of unnamed lineages that are >5% divergent on ND2 across the phylogeny, including three from the gracilis clade on an elevation gradient (800–1400 m asl.) around Yercaud in the Shevaroy massif, Salem district, Tamil Nadu. We describe two of these as new species— Cnemaspis shevaroyensis sp. nov. and Cnemaspis thackerayi sp. nov. are both allied to Cnemaspis gracilis and can be diagnosed from all other Indian Cnemaspis by the absence of spine-like scales on flank, heterogeneous dorsal pholidosis, presence of femoral and precloacal pores, tail with enlarged, strongly keeled, conical tubercles forming whorls, a median row of enlarged and smooth sub-caudals. They differ from C. gracilis and each other in body size, the number of tubercles around midbody, the number of tubercles in paravertebral rows, the number of femoral and precloacal pores, the number of poreless scales in-between precloacal pores and between femoral and precloacal pores, and subtle colour pattern differences; besides uncorrected mitochondrial sequence divergence (7.9–16.6 %). We also provide a description of Cnemaspis yercaudensis from its type locality and an additional locality. The discovery of two endemic species and a third unnamed divergent lineage from an isolated massif in peninsular India outside the Western Ghats indicate that many other such understudied hill ranges may harbour high endemic biodiversity. 


2015 ◽  
Vol 298 (3) ◽  
pp. 169-177 ◽  
Author(s):  
N. Lakshminarayanan ◽  
K. K. Karanth ◽  
V. R. Goswami ◽  
S. Vaidyanathan ◽  
K. Ullas Karanth

2012 ◽  
Vol 59 (2) ◽  
pp. 271-280 ◽  
Author(s):  
Tharmalingam Ramesh ◽  
Riddhika Kalle ◽  
Kalyanasundaram Sankar ◽  
Qamar Qureshi

2021 ◽  
pp. 161-174
Author(s):  
Nagarajan Bharathy ◽  
Srinivasan Sowmiya ◽  
Shanmugam Karthik ◽  
Ravichandran Koshila Ravi ◽  
Mayakrishnan Balachandar ◽  
...  

Algunos microbios beneficiosos para el suelo ayudan en el establecimiento y crecimiento de plantas medicinales exóticas. Por lo tanto, evaluamos la presencia y el estado de la asociación de endófitos de raíces [hongos micorrízicos arbusculares (AM) y hongos endofíticos septados oscuros (DSE)] en diez especies de plantas medicinales exóticas cultivadas en Nilgiris de los Ghats occidentales. El alcance de las variables endófitas de hongos y las características del pelo de la raíz difirieron significativamente entre las plantas medicinales. Se identificaron seis morfotipos de esporas de hongos AM en las muestras de suelo. Por lo tanto, este estudio indicó la asociación de plantas medicinales exóticas con hongos nativos AM y DSE que podrían explotarse para promover el crecimiento y aumentar la producción de metabolitos secundarios en estas especies de plantas. Some soil beneficial microbes help in the establishment and growth of exotic medicinal plants. Therefore, we evaluated the presence and status of root endophyte [arbuscular mycorrhizal (AM) fungi and dark septate endophytic (DSE) fungi] association in ten exotic medicinal plant species cultivated in the Nilgiris of the Western Ghats. The AM fungi colonized all the examined plant species and eight plants had the co-occurrence of DSE fungi. The extent of fungal endophyte variables and root hair characteristics significantly differed among the medicinal plants. Six AM fungal spore morphotypes were identified in the soil samples. Thus, this study indicated the association of exotic medicinal plants with native AM and DSE fungi which could be exploited to promote growth and increase secondary metabolite production in these plant species.


2021 ◽  
Vol 13 (1) ◽  
pp. 17548-17553
Author(s):  
Kalesh Sadasivan ◽  
Muhamed Jafer Palot

The genus  Protosticta (Odonata, Zygoptera, Platystictidae) is represented by nine species in the Western Ghats of peninsular India, of which seven are reported for the state of Kerala.  Our recent records of Protosticta rufostigma Kimmins, 1958 from the Western Ghats of Kerala State is discussed, and despite a thorough literature search no collection records or photographs of the species has been found after the original description from Tamil Nadu.  The species is, thus, added to the checklist of odonates of Kerala State. The description of the live insect, its ecology, status and distribution is discussed. 


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