1 / 8

Orconectes rusticus Rusty crayfish

Orconectes rusticus Rusty crayfish.

whannah
Télécharger la présentation

Orconectes rusticus Rusty crayfish

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Orconectes rusticus Rusty crayfish Rusty crayfish O. rusticusare spread by anglers who use them as bait. They are prolific and have serious impacts like severely reducing lake and stream vegetation and depriving native fish and their prey of cover and food. They also reduce native crayfish populations Geographical rangeNative range: Indiana, Ohio, Kentucky, and Michigan in the United States. Known introduced range: Has invaded many areas surrounding it's native range. It has moved as far west as North and South Dakota, north as Canada and Maine, and south as Tennessee. DescriptionAccording to Bowen (1999), “O. rusticus can be identified by it’s more robust claws and by the dark, rusty spots on each side of their carapace. The spots are located on the carapace as though you picked up the crayfish with paint on your forefinger and thumb. The spots may not always be present or well developed on rusty crayfish from some waters. In the spring, males will molt into a sexually inactive form (called Form II) and then molt back into the reproductively competent form (Form I) in summer. Form I males are characterized by large claws, a hook on one pair of their legs, and hardened gonapods. The hook and the larger claws are used for grasping females during mating. Males are usually larger than females of the same age.” Habitat descriptionAccording to Bowen (2003), “O. rusticus inhabit lakes, ponds, and streams. They prefer areas that offer rocks, logs, or other debris as cover. Bottom types may be clay, silt, sand, gravel, or rock. Rusty crayfish inhabit both pools and fast water areas of streams. They generally do not dig burrows other than small pockets under rocks and other debris, although there have been reports of more substantial burrows. O. rusticus need permanent lakes or streams that provide suitable water quality year-round.” General impactsAccording to Bowen (2003), “invading O. rusticus frequently displace native crayfish, reduce the amount and kinds of aquatic plants and invertebrates, and reduce some fishpopulations

  2. Carcinus maenas Green Crab This crab is native to Europe and northern Africa. It has been introduced to the USA, Australia and South Africa. It is a voracious a euryhaline food generalist. The voracious predator in some locations of its introduced range, has caused the decline of other crab and bivalve species. DescriptionMaximum carapace length is 60 mm and slightly wider. It has 5 antero-lateral teeth on each side of the carapace and 3 lobes between the eyes. Colour highly variable, mostly greenish, green-brown and green-grey. Habitat descriptionSalinity tolerance enables distribution in estuariesGeneral impactsVoracious predator. The crab is able to crush mussels and shows a clear potential to negatively threaten mussel farms. ManagementinformationPreventative : Biological control agents such as the parasitic cirriped Sacculina carcinus have been discussed, but have notbeen tested in the wild yet. Invasion pathways to new locationsAquacultureLive food tradePet/aquarium tradeShip ballast waterShip/boat hull fouling This species has been nominated as among 100 of the "World's Worst" invaders

  3. Axis axis Indian Spotted Deer Axis axis is an introduced species of deer from India. It has historically been introduced to various locations because of its desirable qualities as a game species. When herd populations become too large they impact local vegetation and increase erosion. They also forage on a variety of vegetation removing food sources for many native species and domestic cattle. They also carry transmissible diseases and pose an increased threat to human safety in and around highway corridors. Geographical rangeNative range: India, Nepal, and Sri Lanka (Anderson, 1999).Known introduced range: Australasia-Pacific. Europe, North America, and South America (Fox Free Task Force, UNDATED; Council of Europe, 2002; National Park Service, 2004; and Jaksic et al. 2002) DescriptionA. axis is a moderately large deer standing 88-97 cm at the shoulders. It has a rufous brown coat that is covered with white spots on the abdomen, rump, throat, insides of legs and ears, and underside of tail that persist throughout the life of the animal. A dark stripe runs down the back from the nape to the tip of the tail. A gland-bearing cleft is present on the front of the pastern of the hind foot. Weights can top 30-75 kg in males and 25-45 kg in females (Anderson, 1999; and Davis and Schmidly, 1997). Antlers are present only on bucks. Occurs in:agricultural areas, coastland, natural forests, planted forests, range/grasslands, scrub/shrublands, urban areas Management informationThe most successful control strategies currently for A. axis to date has been a combination of fencing and hunting. Fencing is not 100% effective though, and deer eventually escape (downed trees, human poaching). A. axis can also jump over 6 foot tall fencing and studies show that 10 foot or higher fencing is required to adequately keep A. axis out of or in an area. Reproductive control using such techniques as contraception and sterilization are also possibilities but are expensive and time consuming requiring many man hours of labor intensive field work. New Zealand controls its exotic deer populations through recreational and commercial hunting and these have been very effective techniques. Once A. axis become established in urban and suburban areas hunting does not remain a practical method of control, therefore it is best to gain control of A. axis populations before they become established in suburban areas (Anderson, 1999; and the University of Hawai‘i, UNDATED).

  4. Eleutherodactylus coqui Eleutherodactylus coqui is a relatively small tree frog native to Puerto Rico. The frogs are quite adaptable to different ecological zones and elevations. Their loud call is the main reason they are considered pests. E. coqui's mating call is its namesake, a high-pitched, two-note "co-qui" (ko-kee') which attains nearly 100 decibels at 0.5 meters. E. coqui have a voracious appetite. There is concern in Hawai‘i, where it has been introduced, that E. coqui may put Hawai‘i’s endemic insect and spider species at risk and compete with endemic birds and other native fauna which rely on insects for food. Caribbean tree frog Geographical rangeNative range: South America: Puerto Rico (Beard et al. 2003).Known introduced range: Australasia-Pacific, North America (USGS-NAS, 2004). Galapagos Islands (Snell and Rea, 1999) Management informationPreventative measures: Intentional transport of frogs has been banned in Hawai‘i (Kraus and Campbell, 2002). Physical: Hand-capture is a successful method when dealing with small numbers (Kraus and Campbell, 2002). Chemical: Field trials are being conducted to evaluate the efficacy of a direct spray application of a concentrated caffeine and water solution for control on 0.1 - 0.5 ha infested plots. If these trials are successful, it is hoped that management agencies in the State of Hawai‘i will be able to reduce the spread and potential impact of these pest species on a landscape scale. (Campbell et al. 2002). Spraying of citric acid on infested plants to kill coqui frog eggs, juveniles, and adults, is recommended (CTAHR, Undated) but evidence of efficacy has not been demonstrated. Occurs in:agricultural areas, natural forests, planted forests, riparian zones, urban areas, wetlands This species has been nominated as among 100 of the "World's Worst" invaders

  5. Lygodium microphyllum small leaf climbing fern Occurs in:natural forests, riparian zones, wetlands Geographical rangeNative range: Africa, Asia, Australasia-Pacific, Europe-Asia (USDA-GRIN, 2005).Known introduced range: North America (University of Florida, 2001). Description"L. microphyllum is a fern with dark brown, wiry rhizomes and climbing, twining fronds of indeterminate growth, to 30 m (90 ft) long; main rachis (leaf stalk above petiole) wiry, stemlike. Leafy branches off main rachis (constituting the pinnae) once compound, oblongish in overall outline, 5-12 cm (2-5 in) long. Leaflets (pinnules) usually unlobed, stalked, articulate (leaving wiry stalks when detached); leaf-blade tissue usually glabrous below; fertile leaflets of similar size, fringed with tiny lobes of enrolled leaf tissue covering the sporangia along the leaf margin." (University of Florida, 2001). General impactsPemberton et al. (2003) refers to L. microphyllum as, "An aggressive invasive weed of moist habitats in Florida. This rapidly spreading weed colonizes new areas without the need of habitat disturbance and frequently completely dominates native vegetation. Herbicidal and mechanical controls are expensive, temporary solutions, and are damaging to non-target plants." Once L. microphyllum has established, "It climbs and blankets other vegetation, ultimately causing mortality to mature canopy and subcanopy trees Sometimes, L. microphyllum covers other vegetation so completely, it is not possible to see other plants beneath it Near the ground surface, a thick mat of old and new fronds also forms, ultimately smothering and stifling native plants including herbs and tree seedlings that would ordinarily maintain the forest canopy if allowed to mature.“ similarly report that, "L. microphyllum forms dense mats of rachis plant material. These thick, spongy mats are slow to decompose, exclude native understory plants, and can act as a site for additional fern colonization. It is difficult for other plant species to grow through the dense mat made by this fern, thereby reducing plant diversity. Large expanses of fern material also may alter drainage and water movement."

  6. Mus musculus Linnaeus house mouse The house mouse probably has a world distribution more extensive than any mammal apart from humans. Its geographic spread has been facilitated by its commensal relationship with humans which extends back at least 8,000 years. They do considerable damage by destroying crops and consuming and/or contaminating food supplies intended for human consumption. They are prolific breeders, sometimes errupting and reaching plague proportions. They have also been implicated in the extinction of indigenous species in ecosytems they have invaded and colonised which are outside their natural range. An important factor in the success of the house mouse is their behavioural plasticity brought about by the decoupling of genetics and behaviour. This enables the house mouse to adapt quickly and to survive and prosper in new environments. Occurs in:agricultural areas, coastland, disturbed areas, natural forests, planted forests, range/grasslands, riparian zones, scrub/shrublands, urban areas DescriptionA long tail (60-105 mm - approximately equal to its head and body length of 65-95 mm), large prominent black eyes, round ears and a pointed muzzle with long whiskers. Adults 12-30 g. Wild mice are commonly light brown to black; belly fur white, brown, or grey. Colour of tail also lighter below than above. Geographical rangeNative range: Native to the Indian subcontinent, the house mouse has accompanied humans to, and colonised, tropical, temperate, semi-desert, desert, and subantarctic regions throughout the world. General impactsHouse mice are major economic pests, consuming and despoiling crops and human foodstuffs, and have also been implicated in extirpations and/or extinctions of indigenous species in ecosytems they have invaded and colonised which are outside their natural range. They are host to a range of diseases and parasites infectious to humans, the most serious being bubonic plague (Yersinia pestis) and salmonella (Salmonella spp.). However, mice are considered relatively unimportant as vectors for their transmission to humans. This species has been nominated as among 100 of the "World's Worst" invaders

  7. Norops sagrei can be identified by its extensible throat fan that is often coloured yellow or reddish-orange and has a white line down the centre of its backside. This species is a habitat generalist that prefers open vegetation of disturbed sites. N. sagrei is a ground dweller but will venture up several feet into trees and shrubs. This species competes with Anolis carolinensis and other introduced congeners. N. sagrei also prey on the hatchlings of A. carolinensis. Norops sagrei Brown Anole Occurs in:disturbed areas, urban areas Geographical rangeNative range: The brown anole is native to Cuba, the Bahamas, and their satellite islands (Campbell, 2002). Known introduced range: North America, Hawai‘i, Jamaica (Campbell, 2002). They have also been introduced into Granada (Kolbe et al 2004). DescriptionN. sagrei or brown anole is a “trunk ground ecomorph” sensu. It is described as having an extensible throat fan that can be yellow to red-orange. This species can be between 13 and 21.3 cm. It also has enlarged toe pads and a short snout. N. sagrei can erect a dorsonuchal crest when exposed to certain stimuli. The tail may have a crest-like ridge, but this is highly variable between individuals and should not be confused with the dorsonuchal crest. Also, the tail is laterally compressed. Females have a light line down the middle of their backs, but males do not. They tend to have a lighter mid-dorsal stripe that is distinct and often boldly patterned in females and often indistinct in males. Individuals change their colors and patterns throughout this range. Male color is highly variable, ranging from light gray to nearly jet-black, and plain colored to covered dorsally with irregular dark patches or chevrons and a network of light lines. Females exhibit a large range of color, but nearly always have some type of obvious wavy dorsal pattern along the midline of their back. Management informationCampbell (2002) observes that, no control or eradication measures have been implemented for the brown anole, in Florida (North America) where it has established. He further adds that this species would be very difficult if not impossible to completely eradicate due to its high density, high reproductive potential, and habitat generality.

  8. Rana catesbeiana Bullfrog The North American bullfrog Rana catesbeiana has been widely distributed via aquaculture and the aquarium trade. It is one of the most frequently cultivated edible frogs, world-wide. Primary concerns are competition with and predation upon native herpetofauna. DescriptionLarge size: adults 10-20 cm snout-to-vent length and 60-900 g. Dorsal color is light green to olive to brownish-green, often with a mottled pattern of greens and browns. A fold of skin runs from the eye around conspicuous eardrums. The mostly white ventral surface may be mottled with gray. Occurs in:lakes, water courses, wetlands General impactsCompetes with native anurans. Larvae can have a significant impact upon benthic algae, and thus perturb aquatic community structure. Adults may be responsible for significant levels of predation on native anurans and other aquatic herpetofauna, such as snakes and turtles. These impacts have been documented for bullfrogs on the west coast of the United States and they are the likely ones for the species globally. Geographical rangeNative range: The bullfrog is native to central and eastern USA and southeastern Canada. Known introduced range: It has been introduced to Hawaiii'i, parts of western USA and southwestern Canada, Mexico and the Caribbean, South America, Europe and Asia. This species has been nominated as among 100 of the "World's Worst" invaders

More Related