The status and implications of alien invasive species in Sri Lanka

Abstract

Alien invasive species (AIS) is one among the various threats to the biodiversity of Sri Lanka. A survey was carried out to establish the present status of AIS in Sri Lanka. Wetland and terrestrial ecosystems of different climatic zones were surveyed randomly for the presence of AIS and their threats. Among the 59 AIS identified, 10 species of fauna and 13 species of flora are included in the list of 100 of the world's worst AIS. The alien invasive fauna of Sri Lanka includes 15 vertebrates and 5 invertebrates. The paper discusses the impact of alien invasive fauna and flora on the native species and stresses the need for a proper management strategy.

Transcontinental dispersal, ecological opportunity and origins of an adaptive radiation in the Neotropical catfish genusHypostomus(Siluriformes: Loricariidae)

“…Invasive and often ecologically destructive populations of Hypostomus are now established in many drainages around the world, including rivers in Texas (Pound et al . ), Sri Lanka (Bambaradeniya ) and China (Xu et al . ).…”

“…5;Saint-Paul et al 2000), they are also among the most adept of all loricariid genera at invading novel habitats outside their native range. Invasive and often ecologically destructive populations of Hypostomus are now established in many drainages around the world, including rivers in Texas (Pound et al 2011), Sri Lanka (Bambaradeniya 2002) and China (Xu et al 2012). Hypostomus is one of only two loricariid genera to have broadly established invasive populations outside their native range, the other being the closely related genus Pterygoplichthys (Capps & Flecker 2013).…”

Challenges in Biodiversity Conservation in a Highly Modified Tropical River Basin in Sri Lanka

“…This basin, particularly its urban and residential reaches, hosts several alien fish species including Clarias batrachus (Walking catfish), Chitala ornata (Clown featherback), Pterygoplichthys cf. disjunctivus (Vermiculated Sailfin Catfish), Poecilia reticulata (Guppy), Oreochormis mossambicus (Mozambique Tilapia), O. niloticus (Nile Tilapia), Trichopodus pectoralis (Snakeskin gourami), T. trichopterus (Three-spot gourami), and Helostoma temminkii (Kissing gourami) [20,[83][84][85]. Moreover, other aquatic exotic invaders-Trachemys scripta (Red-eared slider, a turtle) and Pomacea diffusa (Apple snail) in particular-have been documented along the lower reaches of the river (HS, personal observations).…”

“…These alien species compete with native fishes for critical resources such as food, habitats, and nesting grounds (Oreochromis species) [22]. Predatory alien fish (Clarias batrachus and Chitala ornata) prey on small-sized native fish, while Poecilia reticulata feeds on native amphibian eggs [84]. These exotic species can change habitat structure and ecological processes, rendering habitats unsuitable for native freshwater biota.…”

Impacts of <em>Ageratina riparia (Regel) R. M. King & H. Rob.</em> on natural regeneration of sub-montane forests at Knuckles Forest Reserve, Sri Lanka

“…Although Sri Lanka is a small tropical island, a wide range of topographic and climatic variations in the country have led to evolution of many types of ecosystems, with high level of biodiversity per unit area, that is higher than most of other countries in the region (Bambaradeniya, 2002). When considering the forest cover of Sri Lanka, the richest biodiversity of the country is in the southwest of the country which include, 670 km 2 of montane forest, 740 km 2 of lowland forest, a total of 1,410 km 2 (roughly half being primary forest), or a mere 9% of original forest covering almost 16,000 km 2 (Myers, 1990).…”