White umber
| White umber | ||||||||||||
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White umber ( Genyonemus lineatus ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Genyonemus | ||||||||||||
| Gill , 1861 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Genyonemus lineatus | ||||||||||||
| ( Ayres , 1855) | ||||||||||||
The white umber ( Genyonemus lineatus ) (English: White Croaker or Spanish: Roncador blanco ) is a umber fish from the North American west coast. It was originally described in 1855 by William Orville Ayres as Leiostomus lineatus , but later placed in its own genus with the name Genyonemus . The word Genyonemus could be translated with "chin thread" - although the White Umber no Bartel has. But it is now clear that “Genyonemus” is a typographical error in the manuscript or (more) a reading error of a typesetter: for Genyanemus (“chin without thread”!). If you want to be subtle, you could also explain the name as a haplology of “Genyonenemus” (which would mean “chin without a beard”).
features
The body of the white umber is elongated and slightly flattened on the sides. The head is bluntly rounded, the mouth is slightly below, as with most fish, which mainly look for their food on the bottom. Its color is pale brownish to yellowish, towards the back too silvery. The fins are yellow to white. The white umber is quite similar to the eye spot umber ( Leiostomus xanthurus ) in size (up to just over 40 cm) and way of life. It has no eye spot , but sometimes a dark-colored, small "spoiler" (axillary scale) on the base of the pectoral fin.
Like the eyespot umber, the white umber is monotypical , i.e. the only species in its genus. It has 25 vertebrae .
Rays : D1 XII – XV, D2 I / 20–23, A II / 10–12.
The 12–15 rays of the first dorsal fin distinguish the white umber from all other umberfishes with a lower mouth, as they have no more than 11 fin rays. It does not have a fleshy appendage ( Bartel ) on the tip of the chin like Menticirrhus undulatus from the related genus of the king fish and Umbrina roncador from the genus Umbrina , which occur in the same distribution area.
habitat
Its occurrence extends along the west coast of the North American continent between Baja California and Barkley Sound in British Columbia , but its abundance is rapidly decreasing north of San Francisco .
On the west coast, the white umber is the vicarious species of the related eye-spot umber from the North American east coast, ie it represents it geographically, but has ecological claims similar to this. It swims over sandy bottom and feeds on bristle worms , small shrimp , crabs and mollusks .
It is also a much-caught and tasty fish, but insignificant for sport fishermen like the eye-spot umber - only to be used as bait.
literature
- William N. Eschmeyer, ES Herald and H. Hammann: A field guide to Pacific coast fishes of North America. Houghton Mifflin Company, Boston 1983
Web links
- White Umber on Fishbase.org (English)
- California Marine Sportfish: White croaker (Description)
- Genyonemus lineatus inthe IUCN 2013 Red List of Threatened Species . Posted by: Chao, NL & Starnes, WC, 2009. Retrieved February 7, 2014.