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Exploring the beautiful nature of California
California Nature: Chub
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California is a large state, the 3rd largest
in the U.S.A., and depending on where you go, can range broadly
in habitat type and, also, climate. For this reason, California
plays host to a huge variety of fish.
Fishes are aquatic vertebrates that have fins, gills and
scales. Gills are the part of the respiratory system that
provide surface area for exchanging oxygen and carbon dioxide
under water. Fish are ectotherms, commonly referred to as
'cold-blooded', meaning their temperature is regulated by the
temperature of their environment. They have a range of diets,
being herbivores, carnivores, or omnivores. Some fish reproduce
by laying eggs, while others reproduce by bearing live young.
California fish species reside in freshwater and
coastal/marine waters. Freshwater fish are fishes that live at
least part, if not all, of their lives in bodies of fresh water
with a salinity of less than .05%. Forty-one percent of all
known fish species are found in freshwater.
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Usually less than 4 inches, the arroyo chub is a small, chunky minnow found in slow moving
mud or sand bottomed sections of streams. They have gray-olive green backs and white
bellies, fairly large eyes, and small mouths. Arroyo chubs eat algae and small insects and
other invertebrates that they pick off of plants or off the bottom.
Arroyo chub breed from
February through August, and during the breeding season, males develop bumps, called
breeding tubercles, on their pectoral fins.
The Arroyo chub is native to the Los Angeles, San Gabriel, San Luis Rey, Santa
Ana, and Santa Margarita rivers and to Malibu and San Juan creeks. They have been
introduced to the Santa Ynez, Santa Maria, Cuyama, and Mojave river systems, and to a
number of smaller coastal streams.
Currently, arroyo chub are absent or rare in much of their
native range, and are only abundant in portions of the Santa
Margarita River and Trabuco, San Juan, and Malibu Creeks.
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Arroyo chub is threatened by habitat
modification due to urbanization, and by competition with
introduced minnow species such as the red shiner. It was
declared a Fish Species of Special Concern in California by the
Department of Fish and Game in 1995, and the department
recommends protection and management of any remaining natural
stream habitat in their range, and establishment of a native
fish refuge in the West Fork of the San Gabriel River for
conservation of arroyo chub.
In the early 1970s the Mohave Tui Chub population in the Mojave
River experienced a significant loss. In order to save the
population, wildlife officials moved some of the populations to
safer habitat and one of those places was China Lake.
Mohave tui chubs are small fish rarely exceeding 6.7 inches, but occasionally reaching 8.7 inches. The body is stocky with a large, slightly concave head, and short rounded fins.
Larger fish may develop a pronounced hump behind the head. The snout is short and the mouth is
slanted downward posteriorly. In color, these endangered fish are bright
brassy-brown to dusky-olive dorsally, with gold and fine
speckling laterally, and a bluish-white to silver ventral
surface. |
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The Bonytail Chub is on the U.S. Endangered Species List, classified as endangered throughout its range in Arizona,
California, Colorado, Nevada, and Utah. This fish lives in
large, fast-flowing waterways of the Colorado River system, and
the large-scale damming of the river has diminished available
habitat. Other threats to the Bonytail Chub
have been the introduction of non-native fish that compete for
food and habitat, and may prey on it or hybridize with it.
A bonytail chub can grow to over 2 feet long. Like many other desert fishes, its coloring tends to be darker above and lighter below, serving as a camouflage. Breeding males have red fin bases. They have a streamlined body and a terminal mouth. Bonytail Chubs have bodies that sometimes arch into a smooth, predorsal hump.
While their skull is quite concave, their tailside is thin, and almost looks like a pencil
( “bony tail”). The coloration of Bonytail Chubs is usually dark
dorsally and lighter ventrally, however, in very clear waters,
they looks almost black all over. |
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