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Hobbseus orconectoides

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA ARTHROPODA MALACOSTRACA DECAPODA CAMBARIDAE

Scientific Name: Hobbseus orconectoides
Species Authority: Fitzpatrick & Payne, 1968
Common Name(s):
English Oktibbeha Riverlet Crayfish

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii) ver 3.1
Year Published: 2010
Date Assessed: 2010-06-01
Assessor(s): Adams, S., Cordeiro, J. & Jones, R.L.
Reviewer(s): Collen, B. & Richman, N.
Contributor(s): Livingston, F., Livingston, F., Soulsby, A.-M., Batchelor, A., Dyer, E., Whitton, F., Milligan, H.T., Smith, J., Lutz, M.L., De Silva, R., McGuinness, S., Kasthala, G., Jopling, B., Sullivan, K. & Cryer, G.
Justification:
Hobbseus orconectoides has been assessed as Endangered under criterion B1ab(iii). This species has an extremely restricted range with an area of occupancy of approximately 13 km2 and is presently only known from 2 locations. The quality of habitat in this species range is under threat from urban development and resulting pollution which has already resulted in the extirpation of this species from the type locality. It may be found from other sites but these are not likely to more than triple the area occupied. Further research on the population trends of this species is suggested to better understand at what rate it is being lost and devise effective conservation measures.
History:
1996 Vulnerable

Geographic Range [top]

Range Description: This species was known only from Lowndes, Oktibbeha, and Webster counties, Mississippi, USA (Fitzpatrick and Payne 1968). Many of the sand creek accounts may not still be in existence (S. Adams, pers. comm. 2009). The distribution of this species is severely fragmented (S. Adams, pers. comm. 2009). Following recent surveys of this species distribution between 2007 and 2009, it is believed to only occur in the Sand Creek drainage in Oktibbeha County, despite reports from two other counties (R.L. Jones pers. comm. 2010). As such this species is currently believed to exist at only two locations less than 216 m apart (R.L  Jones pers. comm. 2010). One of these is a tributary of Sand Creek and the other is a ditch and pond along the side of a dirt road. 

The extent of occurrence (EOO) of this species has been estimated at around 291 km2 (R. L. Jones pers. comm. 2010). The area of occupancy is calculated at 13 km2. It is possible that this species may be known from other localities, but this would not more than double or triple the area occupied (R.L. Jones pers. comm. 2010).

Countries:
Native:
United States (Mississippi)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population:

There are insufficient population data available for this species, although Fitzpatrick (2002) describes the species as never abundant but moderately plentiful at the type locality. Seeing as the type locality is now completely devoid of this species, the more abundant of the two remaining locations is the creek, in which it is not common (R.L. Jones pers. comm. 2010).  

Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: This species occurs in lentic habitat such as ponds, puddles, ditches, and also in lotic habitats such as streams (Fitzpatrick and Payne 1968). It is further found in association with emergent vegetation and littoral zones (Fitzpatrick and Payne 1968). This species burrows during the summer dry periods and is a secondary burrower (Hobbs 1989).Currently this species has only been found in two locations: a moderately flowing creek approximately two meters wide, 30 cm deep, with a sand and clay bottom, and a roadside ditch approximately 1 m wide and 30 - 40 cm deep with a silt bottom and some aquatic vegetation (R.L. Jones pers. comm. 2010).
Systems: Freshwater

Threats [top]

Major Threat(s): This species is threatened by habitat degradation through residential and urban developments at its type locality, from which it is now believed to have been extirpated. These developments result usually in complete destruction of the small streams which this species requires (R.L. Jones pers. comm. 2010). In addition, development over intermittent ponds is known to remove habitat (S. Adams, pers. comm. 2009, R.L. Jones pers. comm 2010).  Due to its restricted distribution and occurrence in one area (two locations 216 metres apart) this species is extremely susceptible to threats.

Conservation Actions [top]

Conservation Actions: This species has been given the Global Heritage Status Rank of G1 by NatureServe (Taylor et al. 2007, NatureServe 2009) and 'threatened' by the American Fisheries Society (Taylor et al. 2007) based on a loss of habitat quality, and a restricted range.

Further research on population trends for this species is needed.

Citation: Adams, S., Cordeiro, J. & Jones, R.L. 2010. Hobbseus orconectoides. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 31 August 2014.
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