Glyphis sp. nov. A

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	CHONDRICHTHYES	CARCHARHINIFORMES	CARCHARHINIDAE

Scientific Name:

Glyphis sp. nov. A

Species Authority:

Common Name/s:

English

–

Bizant River Shark

Assessment Information [top]

Red List Category & Criteria:	Critically Endangered C2a(i) ver 3.1
Year Assessed:	2003
Assessor/s	Pogonoski, J. & Pollard, D. (SSG Australia & Oceania Regional Workshop, March 2003)
Evaluator/s:	Fowler, S. & Cavanagh, R.D. (Shark Red List Authority)
Justification: Based on the very few specimens collected to date from just two rivers, this undescribed fresh to brackish water species is possibly a northern Australian endemic, and presumably very rare. Surveys targeting freshwater and estuarine elasmobranchs in northern Australia (Western Australia, Northern Territory, Queensland) in mid-late 2002 collected no Glyphis specimens, despite sampling in 136 sites in 38 rivers. It is inferred that the population contains fewer than 250 mature individuals and that no subpopulation contains more than 50 mature individuals, further that it is presumably threatened by bycatch in commercial and recreational fishing activities and by possible habitat degradation. Future sampling in northern Australian rivers may yet reveal this species to be more abundant than currently known. However, until a time when its abundance can be proven to be greater than current levels, the species is classified as Critically Endangered.

Geographic Range [top]

Range Description:	This species is based on two specimens collected in 2 m of water in the Bizant River in northern Queensland in March 1982 (Last and Stevens 1994, Fowler 1997). Additional specimens were collected in the Adelaide River, Northern Territory in 1999. A recent survey of freshwater elasmobranchs using gillnets and longlines in northern Australia (Kimberleys, Western Australia east to the Cape York drainages of Queensland) yielded no additional specimens of this species despite collecting in 38 rivers and 136 sites (J. D. Stevens, pers. comm. March 2003).
Countries:	Native: Australia (Northern Territory, Queensland)
FAO Marine Fishing Areas:	Native: Pacific – western central

Population [top]

Population:	The population size is unknown, but is suspected to be small based on current knowledge and their apparent rarity. The number and size of subpopulations is also unknown. All populations need to be preserved to maintain the genetic diversity within this species. Kakadu National Park (Northern Territory) is probably an important site for this species as it may be afforded more protection here than in other areas.
Population Trend:	Decreasing

Population:

The population size is unknown, but is suspected to be small based on current knowledge and their apparent rarity. The number and size of subpopulations is also unknown. All populations need to be preserved to maintain the genetic diversity within this species. Kakadu National Park (Northern Territory) is probably an important site for this species as it may be afforded more protection here than in other areas.

Population Trend:

Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	This species may be largely restricted to the freshwater and brackish reaches of rivers, but further research is required on its habitat preferences. The ecology (i.e., critical habitat, salinity tolerances) and life history parameters (age and size at maturity for males and females, litter sizes, longevity) of this species need further investigation. The small eyes and slender teeth of Glyphis species suggest that they are primarily fish eaters adapted to living in turbid waters with poor visibility (Compagno 1984, Fowler 1997).
Systems:	Freshwater

Habitat and Ecology:

This species may be largely restricted to the freshwater and brackish reaches of rivers, but further research is required on its habitat preferences. The ecology (i.e., critical habitat, salinity tolerances) and life history parameters (age and size at maturity for males and females, litter sizes, longevity) of this species need further investigation. The small eyes and slender teeth of Glyphis species suggest that they are primarily fish eaters adapted to living in turbid waters with poor visibility (Compagno 1984, Fowler 1997).

Systems:

Freshwater

Threats [top]

Major Threat(s):	As with other species of the genus, Glyphis sp. A may be largely restricted to freshwater and brackish reaches of rivers. Some of the most threatened chondrichthyan species are those restricted to such habitats, and with naturally very small populations. In addition to all the biological constraints of the marine chondrichthyans, freshwater/brackish species are more seriously limited by threats (such as fisheries and habitat degradation) affecting their restricted populations than are more widely ranging marine species (Compagno 2002). Glyphis sp. A is likely to be threatened by both commercial and recreational fishing and possible habitat degradation. Commercial fishing may be in the form of gillnetting (legal or illegal) or longlining. Recreational fishing may be in the form of illegal gillnetting or hook and line fishing (using bait and/or lures). The potential impacts of fishing operations on this species need further investigation.

Major Threat(s):

As with other species of the genus, Glyphis sp. A may be largely restricted to freshwater and brackish reaches of rivers. Some of the most threatened chondrichthyan species are those restricted to such habitats, and with naturally very small populations. In addition to all the biological constraints of the marine chondrichthyans, freshwater/brackish species are more seriously limited by threats (such as fisheries and habitat degradation) affecting their restricted populations than are more widely ranging marine species (Compagno 2002). Glyphis sp. A is likely to be threatened by both commercial and recreational fishing and possible habitat degradation. Commercial fishing may be in the form of gillnetting (legal or illegal) or longlining. Recreational fishing may be in the form of illegal gillnetting or hook and line fishing (using bait and/or lures). The potential impacts of fishing operations on this species need further investigation.

Conservation Actions [top]

Conservation Actions:	This species is listed as Critically Endangered on the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999. A Recovery Plan is currently being drafted and will be completed by mid 2003 (S. Williams, Environment Australia, pers. comm. March 2003). It is also listed as an Endangered species under the Territory Parks and Wildlife Conservation Act 2000, but no management program was in place as of June 2002 (Stirrat and Larson 2002).

Conservation Actions:

This species is listed as Critically Endangered on the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999. A Recovery Plan is currently being drafted and will be completed by mid 2003 (S. Williams, Environment Australia, pers. comm. March 2003). It is also listed as an Endangered species under the Territory Parks and Wildlife Conservation Act 2000, but no management program was in place as of June 2002 (Stirrat and Larson 2002).

Citation:	Pogonoski, J. & Pollard, D. 2003. Glyphis sp. nov. A. In: IUCN 2008. 2008 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 09 January 2009.
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