Shortspine thornyhead

The shortspine thornyhead (Sebastolobus alascanus) is a species of fish in the family Sebastidae. It is sometimes referred to as the "idiot fish" or "idiot cod" due to its large oversize head/eyes. It is found in Canada, Russia, and the United States. Adult S. alascanus live predominantly in the oxygen minimum zone (OMZ), and thus require specific adaptations/exaptations in order to overcome the problems posed by the extremely low levels of oxygen saturation. Allowing for an increased ventilation frequency during exposure to progressively hypoxic conditions, as compared to its more shallow relative Scorpaena guttata, enables S. alascanus to compensate for the inherent low concentrations of oxygen in the OMZ. Further, heightened levels of lactate dehydrogenase, specifically the anaerobic isoform- LDH-A in the heart and muscles of S. alascanus, suggests an adaptive mechanism for ATP production during low oxygen availability.

Shortspine thornyhead
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Actinopterygii
Order:
Scorpaeniformes
Family:
Sebastidae
Genus:
Sebastolobus
Species:
S. alascanus
Binomial name
Sebastolobus alascanus

Description

The shortspine thornyhead has a large head with a strong spiny ridge, and an elongate, tapering body which grows to a maximum length of 80 cm (31 in). The dorsal fin has 15 to 17 spines and 8 to 9 soft rays and the anal fin has 3 spines and 4 to 5 soft rays. There is a deep notch in the pectoral fin and the caudal fin is rounded. The general color of this fish is bright red with varying amounts of black on the fins and a pale-colored gill chamber. This fish may live for 100 years.[2]

Distribution

The shortspine thornyhead is native to the cold waters of the northern Pacific Ocean and is known from Canada, Alaska and the Russian Federation. Its depth range is between 17 and 1,600 m (56 and 5,249 ft) but it is more usually found at depths less than 100 metres (330 ft).[2]

Status

Separate stock assessments for Shortspine thornyhead in the waters off Alaska, British Columbia, and the West Coast of the United States have all estimated the stock as healthy (above the management limits) with overfishing not occurring.[3][4][5] The IUCN status is listed as "Endangered" based on an assessment conducted in 2000.[1]

References
  1. Bell, T. & Guttman, A. (2000). "Sebastolobus alascanus". IUCN Red List of Threatened Species. 2000: e.T29609A9504511. doi:10.2305/IUCN.UK.2000.RLTS.T29609A9504511.en.
  2. "Sebastolobus alascanus Bean, 1890: Shortspine thornyhead". FishBase. Retrieved 2013-12-20.
  3. Echave KB, Hulson PJ, Shotwell SK (2015), Assessment of the Thornyhead stock complex in the Gulf of Alaska, in Stock Assessment and Fishery Evaluation Report for the Groundfish Resources of the Gulf of Alaska (PDF), 605 W 4th Ave, Suite 306, Anchorage AK: North Pacific Fishery Management CouncilCS1 maint: location (link)
  4. DFO (2016), Stock assessment of the coastwide population of Shortspine Thornyhead (Sebastolobus alascanus) for British Columbia, Canada in 2015 (PDF), DFO Can. Sci. Advis. Sec. Sci. Advis. Rep.
  5. Taylor IG, Stephens A (2013), Stock Assessment of Shortspine Thornyhead in 2013 (PDF), Portland, OR: Pacific Fishery Management Council
  • Yang, et al. (1992). "Respiratory, Blood, and Heart Enzymatic Adaptations of Sebastolobus alascanus (Scorpaenidae; Teleosti) to the Oxygen Minimum Zone: A Comparative Study". Biological Bulletin 183: 490-499.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.