Pages

Saturday, 20 February 2016

Freshwater Biodiversity Assessments in the Western Ghats

The Western Ghats in India is one of the world’s most heavily populated Biodiversity Hotspots, providing for and supporting 400 million people through water for drinking, transport, irrigation, and hydroelectric power, together with food and resources to sustain livelihoods. However, the pace of growth of the Indian economy and rates of industrial and urban development are not in tune with the conservation needs of this freshwater ecosystem and the remarkably high diversity of species they contain. In most instances the development planning process does not consider the ecosystem’s requirements, mainly due to a lack of adequate information on the distribution and status of freshwater species and the threats they face. There is also little appreciation of the value of freshwater ecosystems to the livelihoods of many people, often the poorest in society. In response to this need for information and raised awareness, the IUCN Global Species Programme’s Freshwater Biodiversity Unit, in collaboration with the Zoo Outreach Organisation (ZOO), conducted the Western Ghats Freshwater Biodiversity Assessment to review the global conservation status and distributions of 1,146 freshwater fishes, molluscs, odonates and aquatic plants.
The geographic scope of the project included all major river catchments with their origin within the Western Ghats Biodiversity Hotspot. The Tapi, Krishna, and Cauvery systems are included, with freshwater species native to the Western Ghats states of Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu, as well as parts of Andhra Pradesh and western and southern portions of Madhya Pradesh, Orissa and Chattisgarh, assessed. The IUCN Red List Criteria, the world’s most widely accepted system for measuring relative extinction risk, were applied to assess the status of all species, with information on each species compiled by more than 40 experts from the Western Ghats and elsewhere.

Thursday, 1 October 2015

Age, Growth and Population Dynamics of an Endangered Fish Sahyadria denisonii (Day 1865) from the Western Ghats Hotspot of India

Abstract:
The population structure, age, growth, mortality and harvest intensity of redline torpedo barb Sahyadria denisonii (Day 1865) in the River Valapattanam was studied using lengthfrequency based analysis. The von Bertalanffy growth functions estimated were Lt=158 [1-e-0.8(t+0.0203)] and growth parameters of von Bertlanffy equation were L= 158 mm, K= 0.8 year-1 and t0= -0.0203. The present level of exploitation (E=0.60) is higher than the Gulland equation (E=0.5) which is an indication of over exploitation. The recruitment pattern was continuous, and displaying a single major peak event per year. Management practices recommend the establishment of a closed season from November to February to protect the spawning stock and stock wise river ranching of captive bred young ones.

Tuesday, 30 June 2015

BREEDING OF SAHYADRIA DENISONII (DAY 1865) (CYPRINIDAE), AN ENDANGERED FISH OF THE WESTERN GHATS, INDIA

ABSTRACT

Over the past few decades wild population of Sahyadria denisonii (Day 1865), an endemic ornamental barb of the Western Ghats of India has been overexploited for aquarium trade and is presently listed under endangered (EN) category in the IUCN Red List. The present study communicates the first ever success of captive breeding and early developmental studies of S. denisonii. Life history phases of S. denisonii were classified into embryonic, larval, juvenile, subadult and adult stages. Spawning season was from November to March in wild and fecundity varied depending on the size and age of breeding pairs. Eggs were obtained through induced breeding using ovaprim hormone at 0.4 ml per kg body weight. Fertilised eggs were adhesive, demersal and attached to any substratum having a diameter of 1184-1312 µm. Hatching took place 36 h after fertilisation at a water temperature of 27.5±0.5ºC. At hatching, mean larval length was 3.5±0.2 mm with high amount of yolk and the yolk sac remained up to 3-4 days. Organogenesis of larvae was completed 15-20 days after hatching. In this paper full developmental sequence from egg to adult stages of S. denisonii in controlled condition is described.