Tui Slough... Constructing an Extension to Deppe Pond (2007 to the present)

After determining in the Spring of 2007 that Deppe Pond would be a good site for the 4th refugium for the endangered Mohave tui chub (MTC), an idea was born to create a larger extension below the existing pond. In August of that year, six students enrolled in AAE's Mojave River Student Scientist class, (a high school science elective giving student hand-on experience in conservation biology, environmental science, and outdoor education) took a trip to Lark Seep on the Naval Air Weapons Stations (NAWS) near China Lake in Ridgecrest, California. There, we were meet by Susan Williams who took us to see a canal to Lark seep called G-1, affectionately called "Chub Med" by fishery biologists, because MTC seem to prefer that habitat it provides.

After comparing the dimensions of the G-1 canal to the space available below Deppe Pond, it was determined that we would try to replicate the G-1 habitat below the existing pond's dam. We eventually called this 300 foot long, 21 foot wide, 3-5 foot deep channel "Tui Slough". What follows is a slide show of the "Tui Slough" site, pre-construction.

In December, 2007, a field construction supervisor was approached one morning on a worksite and asked if his company would consider donating their time to regrade the existing road on the west bank of both Deppe Pond and the Tui Slough site, excavate the 300 foot long, 21 foot wide, 3-5 foot deep channel, and regrade the "Slough's" east bank. A week later, after conferring with the owners, FMK (For My Kids Construction" agreed to donate their time and equipment to do the earth moving work necessary to create the initial, unlined channel. What follows is a slide show of the construction of the "Tui Slough". construction.

After the "Slough" was dug, two students proceeded to do the measuring and math to determine the best estimate for the amount of pond lining material that will be needed to line the ends and three sides of the slough. At present we are waiting on the construction of an additional dam at the end of the "Slough", similar to the one that retains the waters behind Deppe Pond, before we line the slough. If possible, the same contractor that constructed that dam will construct this one as well (Conco Construction of Apple Valley). (3/23/2008)

To be continued...

Preparing Deppe Pond for its New Inhabitants...

In 2000, the Mojave River Campus of the Lewis Center for Educational Research opened its door for the first time. The campus covers 18 of the 53 acres that the Center owns above the Upper Narrows of the Mojave River. Since runoff from the campus, by law, can not go directly into the nearby marsh, wash or river, a unlined retainment basin was built to hold it. This retainment basin is located at the back of the school, between the marsh and the main campus building, and receives runoff from two river-rock lined channels.

In 2002, Bill Deppe, a newly hired veteran teacher and avid birder, started working with his ornithology class to line the pond in the hopes that it could act a resting site for migrating shore birds and water fowl. By 2004, the pond had been lined and started showing the signs of becoming biologically active with willows, cottonwoods,water plants, shore grasses, crayfish, bullfrogs, treefrogs, and water birds along with an occasional visit from western pond turtles and beavers from the nearby Mojave River. Gold fish and mosquito fish were also added to the pond to serve as bird food and mosquito control. It was about this time that Molly Estes and Amanda Pearson offered the suggestion that either the pond or the nearby marsh be used as a refugia for the MTC.

View Larger Map

In the January, 2007, Mr. Huffine received a call from representatives of the California Department of Fish and Game and the United States Fish and Wildlife Service asking if the Lewis Center was still interested in host a refugia for MTC. During Spring Break of the same year, after a visit from Steve Parmenter (CDFG), Judy Holman (USFWS), Michael Glenn (USFWS) and Debra Hughson (NPS), it was determined that Deppe Pond would make a good site for the MTC fourth refugia. However, before the pond could support a respectable population of chub it would need some work.

By August, 2007, the pond, which is now called Deppe Pond, had been lined for almost three years and supported a thick growth of cattails and bullrush. What follows is a time-line that describes Deppe Pond's remediation prior to receiving MTC.

• July-August 2007 - Lower water level and proceed to cut and remove over 90% of the cattail and bull rush, a cooperative agreement between the USFWS and the Lewis Center was being drafted, signed and ratified in advance of the issuing of a $25,000 grant to help create the refugia and begin the effort of educating the public about the MTC and the effort being made to "down-list" the species from being endanger of becoming extinct to merely being threatened with extinction.
• August-December 2007 - Students began to trap out Gold fish, mosquito fish, crayfish bullfrogs and their tadpoles, the grant was received in October
  
• December 2007 - March 2008 - Deppe pond was de-watered, rocks and trash was removed, a 120 foot well, pump and water distribution system was installed, a water aeration unit was installed and was refilled by 3/21/2008.

To be continued...

Tui Chub and the Genetics behind Understanding Them

The following blog is for tracking genetic findings concerning the MTC. First some vocabulary:

• loci - Plural of locus, a site or position on a chromosome where a particular gene or DNA sequence resides. Often used interchangeably with the term 'gene', but locus is more generic.
• ESU - evolutionarily significant unit, a distinct kind (species or subspecies)
  
• AFLPs - amplified fragment length polymorphisms
  
• allozyme - is one of several possible forms of an enzyme, a product of a particular allele at a given gene locus, with different genetic backgrounds, allowing genetic variation between individuals, subspecies or specieis to be deduced.
• basepair - Two of the building blocks of DNA held together by weak bonds. In a DNA molecule, adenine always bonds with thymine (AT), and cytosine always bond s with guanine (CG).
  
• microsatellite - A short sequence of DNA, usually 1 to 4 basepairs (a unit of DNA), that is repeated together in a row along the DNA molecule. There is variation from individual to individual in the number of repeats. There are many places in any organism's genome or DNA that contain microsatellites.
• intraspecific - Term that means "within one species."
• interspecific - Term that means "between two or more different species."
• hybrid - an organism that is the offspring of genetically dissimilar parents or stock.
• introgressive - Infiltration of the genes of one species into the gene pool of another through repeated back-crossing of an interspecific hybrid with one of its parents.
• non-introgressed - not showing an infiltration of genes from one species into the gene pool of another (i.e. between Mohave tui chub and Arroyo Chub)
• backcrossing - To cross (a hybrid) with one of its parents or with an individual genetically identical to one of its parents.
• genetic proximity -
• sympatric - Populations of two or more organisms or species that inhabit the same or overlapping geographic area.
• allopatric - Living in another region; said of populations of species which occupy ranges in different places on the earth's surface such that gene flow between them would be restricted or absent.
• morph - A Morph or morphotype, meaning "form" (from the Latin morpha), is a zoological term that describes local populations or subpopulations of a single species of animal that are phenotypically or behaviourally distinct from the larger population as a whole.
• fixation index (F_ST) is a measure of population differentiation based on genetic polymorphism data (such as SNPs or microsatellites).
• subpopulations - A well-defined set of interacting individuals that compose a proportion of a larger, interbreeding population.
• bottleneck - When a condition or event kills a significant percentage of a population and the survivors of such a bottleneck become the ancestors of future generations (and the genetic characteristics of those who do not survive are deleted from the racial heritage) leaving the surviving population with only the alleles of the survivors.
• founder - an individual(s) drawn from a source population that contribute genetically to the derived subpopulation.

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The following abstract can be found at http://www.desertfishes.org/meetings/2006/DFC_Program_2006_Abstracts_2_sided.pdf

Genetic structure and management history of Mohave tui chub (Siphateles bicolor
mohavensis)

Chen, Yongjiu*1; Parmenter, Steve2; May, Bernie3. (1-North Dakota State University, Department of Biological Sciences; 2-California Department of Fish and Game; 3-The University of California, Davis, Department of Animal Science).

The Mohave tui chub (Siphateles bicolor mohavensis) is the only fish native to the Mojave River, California. Mass intergeneric hybridization with introduced arroyo chubs (Gila orcutti) displaced tui chubs from the Mojave River in the 1930s. Mohave tui chubs persisted in one relictual population, Mohave Chub Spring (MC Spring), from which three refuge populations were derived. Employing 12 microsatellite DNA loci, our study characterized genetic diversity of populations of Mohave tui chub, and examined the taxonomic status of the cyprinid fish common in the Mojave River today. We found only unhybridized arroyo chubs in the Mojave River, and unhybridized Mohave tui chubs in the refugial populations. Population substructure is evident among the four Mohave tui chub populations. Contrary to our expectation, the source population at MC Spring has significantly fewer alleles and lower heterozygosity than populations historically derived from it. Our findings suggest that genetic drift due to a small effective population size in MC Spring has reduced genetic diversity in the five decades since the original transplants were made. A bottleneck of 10 individuals during the founding of the Camp Cady population is reflected in significantly lower genetic diversity and divergence of that population from all others. Two additional refuges possess significantly higher levels of diversity, Lake Tuendae and China Lake. We recommend instituting artificial gene flow to rebuild genetic diversity in MC Spring and Camp Cady, and to better conserve allelic diversity in the species as a whole. New populations established in the future should be derived from Lake Tuendae and China Lake.

To be continued...

On the Waiting List... for Extinction?
(Reprinted here from the Lewis Center's "Knightly News" October & December 2007 issues)

If the High Desert was still in its wild undisturbed state, the Mojave River would support a surface flow roughly 2 to 3 times what it does now and that water would be providing a home for only one kind or species of fish, the Mohave tui chub. The reality, however, is that the river is often dry, flowing below ground only, from its origin in the foothills of the San Bernardino Mountains to its terminus near Baker, its wet backwaters and mountain tributaries supporting more then 18 non-native species of fish, introduced by humans. The chub's habitat, provided by time, geologic forces, climatic change, and now man, was reduced to a Jacuzzi sized pond, 10 feet in width and 4-5 feet in depth, fed by an spring, itself an anomaly of geology, on the shore of an ancient lake, a playa, now called Soda Dry lake near Baker.

Today the Mohave tui chub, classified by state and federal biologists as endangered, is in imminent danger of extinction. Currently its small, restricted population is considered stable to declining. For this reason, biologists are trying to establish additional artificial, non-river based sanctuaries, or what conservation biologists call “refugia”, to encourage population growth. In 2003, Molly Estes and Amanda Pearson (class of 2005) discovered these facts while working on an applied science project in my biology class and committed their final two years at the AAE to find a solution, what they called “a wish for a fish”. Molly and Amanda’s (click on the image at right to view the workshop participants) efforts resulted in an invitation to a three-day workshop of experts in desert fish conservation biology, at Zzyzx, just feet from the spring that some believe was the chub’s last true refuge on earth (click on the image at right to view the workshop participants). At that workshop, Molly and Amanda proposed that an refugia be constructed on LCER’s Mojave River campus, adjacent to the Upper Narrows, one of the few sections of the river that support semi-perennial surface flow. Their proposal was accepted pending a review of acceptable sites by fishery biologists.

Last spring (2007), Judy Holman and Michael Glenn from the United States Fish and Wildlife Service (Ventura office), Steve Parmenter from the California Department of Fish and Game (Bishop office), and Debra Hughson from the United States National Parks (Mojave Desert Preserve) visited the campus’s ponds, slough’s, and the river and reviewed water quality data collected by past and present Mojave River Student Scientists (Hastin Zylstra – ‘05, Eddie Stauffer – ‘08, Aidan Fahnestock – ‘10). Their conclusion was that Deppe Pond would provide and acceptable first phase of a two phase plan to introduce about 1000 chub in the late spring of 2008, providing the majority of the cattails are removed, the addition of an aeration device (to promote mixing and oxygenation of the pond’s waters) and that the pond was managed to maintain a depth of 4-4.5 feet at the deepest to provide cool water during hot summer days. The second phase involves the construction of an additional pond below the first. This pond will be called “Tui Slough” and will be the one of first of its kind that has been constructed solely for the chub. In June a $25,000 dollar grant from the USFW was funded to help with the preparation of Deppe Pond and the construction of “Tui Slough”.

Cattail removal began in early August. A technique researched by Molly Estes and Steve Parmenter was used. Molly’s research earned her a 6th place in the 2004 State Science Fair, just a couple places away from the “Big Bucks”. Soon an aerator will be added (turned on in Feb. 2008), and the pond level will be raised. Plans are currently in place to drill a multipurpose about 200 feet from Deppe Pond and Tui Slough (completed Jan. 2008). Water from this well will be used to augment pond and slough levels while providing the school with an emergency water source in the case of emergency (ie. earthquake). The well will also be used in the school’s efforts to promote groundwater awareness education in public school across the Victor Valley.

To most people, the Mohave tui chub (Siphateles bicolor mohavensis), looks like a goldfish, carp or golden cousin of the Koi. Well it should, it belongs to the same family of fishes known as the Cyprinidae (minnows and carps). Although some of its cousin species, found in other watersheds across the Pacific north and southwest and around the world, are numerous, the Mohave tui chub is not. Why its not is another story.

Until the mid 1800’s, only one fish was native to the Mojave River and its tributaries. The downfall began when a sportsman’s whimsy became reality through the introduction of brown and rainbow trout to Deep Creek’s swift cool waters. To provide prey for these predatory fish, bait fish soon followed. One species of bait fish in particular, the Arroyo Chub, provided a seductive and genetic demise for the Tui Chub.

The Mohave tui chub, as it is known among today’s ichthyologists, is believed to be a refugee, forced from its preferred habitat due to a changing climate during an earlier era of our desert home’s prehistory. Fossil remains of our watershed’s present Chub ancestors have been found in the dry playa sediments of Manix and Lake Mojave, two former “Pleistocene Era” lakes between Barstow and Baker.

The end of the “Pleistocene Era” was punctuated by a change in our hemisphere’s climate that ushered in the end of the last major ice age about 19,000 years before the present (BP) and the “dewatering” of our desert. By about 9,000 years BP, these lakes began to dry, as the declining flow of the Mojave River retreated toward their mountain head-waters. Before the lakes began to dry, however, it is believed that a small population of the ancestral Mohave Tui Chub found refuge in the retreating waters of the Mojave River. It was this remnant of the population that 8,000 years later faced a new challenge to their existence as a unique species.

Remember the Arroyo Chub (Gila orcutti), an introduced bait fish, it just so happens to be a “kissing cousin” to the Mohave tui chub (Siphateles bicolor mohavensis, formerly known as Gila bicolor mohavensis). By 1946, years after the Arroyo Chub had been artificially introduced to the headwaters of the Mojave River, fishery biologists noticed that the Arroyo Chub readily cross bred with the native Mohave tui chub. In 1968, it was observed that the resulting “hybrid” chub species was rapidly replacing the native chub population. By 1970, the only pure genetic strain of Mohave tui chub were found in that small spring mentioned earlier in this article, called MC Spring, and a nearby man-made impoundment called Lake Tuendae .

Since 1968, after attempting to establish self-sustaining populations in streams, lakes and ponds across the Southwest, today only four locations (a lake, a pond, a spring and a seep) in the Mojave Desert provide the Mohave tui chub refugees with their only viable non-native habitats. These locations are collectively called refugia by conservation biologists.

In 1971, the one to three-inch, largely plankton eating Mohave tui chub had been listed as a species in danger of becoming extinct. If more viable refugia can be established along the headwaters of the Mojave River, south of the river’s Upper Narrows, this endangered species can be “down-listed” to threatened. In the future, fish from these new ponds might provide fishery and conservation biologists the stock to reintroduce the Tui chub back into a MojaveRiver, its former refuge. However, another invader, the Asian tapeworm, may now also threaten two of these refugia. This tapeworm is carried by Mosquito fish.

Therefore, one of the final obstacles to providing the chub with optimal habitat is the management and or removal of Mosquito fish from Deppe Pond. These non-native, guppy sized, live bearing fish prefer to eat the eggs and larval of other native fish and amphibians that share the water with them; they eat mosquito larva only when nothing else is available. And to make things worse, they carry parasitic tapeworms that are believed to infect members of the goldfish family of fishes. At present (Fall 2007), a small group of Mojave River Student Scientists are taking on the task of designing a trap to reduce their numbers in Deppe pond so if you see their creative two and three liter bottle traps floating on and below the waters of the pond then you know their research is underway. Future plans include allowing the pond level to drop and freeze in the winter once Tui Slough is up and stocked.

As we can make for information available, we will. Stay tuned for more exciting news as we help the Mojave River's only native fish get off the “waiting list for extinction”. If you want to join Molly and Amanda’s fight for this little fish, let me know at mhuffine@lcer.org or 760-946-5414 ext. 238. For more information about the Chub go on line to
http://www.lewiscenter.org/local/tuichub.php

Tui is from the Paiute Indian name for S. bicolor, “tui-pagwi,” with “pagwi” presumably being the Paiute word for minnow.

Siphateles (siphon, tube; ateles, imperfect, referring to incomplete lateral line on young specimens) first used by E. D. Cope in 1883 to describe tui chubs.

Formerly a subgenus of Gila, the recognition of Siphatelesas a full genus follows Mayden and Simons (1998) and unpublished evidence presented by Harris and Markle (2001). Only one species, the polytypic S. bicolor, is listed at this time; two other species, Gila alvordensis and G. boraxobius, will likely be assigned to Siphatele spending a formal taxonomic revision. The distribution and number of taxa referable to S. bicoloris under investigation. Harris and Markle (2001) recommend recognition of nine allopatrically distributed species: S. bicolor, S.
columbianus, S. eurysomas, S. isolatus, S. mohavensis, S. newarkensis, S. obesus, S. thalassinus, and an unnamed species from Silver Lake, OR. I defer listing these taxa as full species pending formal publication. Instead, I list all forms that have at least some taxonomic support for subspecific recognition. Smith et al. (2002) list several unnamed fossil forms. Tui is from the Paiute Indian name for S. bicolor, “tui-pagwi,” with “pagwi” presumably being the Paiute word for minnow.

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Adapted from page 43 of Scharpf's 2005 Checklist of North American Fishes, Part 1

Genetics, hindsight, and recovery of Mohave tui chub From Program for San Luis Obispo...

Parmenter, Steve1, Chen, Yongjiu2, Bernie May2
1 California Department of Fish and Game, 407 West Line Street, Bishop, CA 93514, Spar@dfg.ca.gov
2 Genomic Variation Laboratory, Department of Animal Science, the University of California, Davis, CA 95616

Mohave tui chub (Siphateles bicolor mohavensis [Snyder]) is the only fish native to the Mojave [sic] River, California. Mass intergeneric hybridization with introduced arroyo chub (Gila orcutti [Eigenmann and Eigenmann]) displaced tui chubs from the Mojave River in the 1930s. Mohave tui chubs persisted in one relictual population, Mohave Chub Spring (MC Spring), from which three refuge populations derive. Employing 12 microsatellite DNA loci, our study characterized genetic diversity of each Mohave tui chub population, compared them with other tui chub taxa, and examined the taxonomic status of the common cyprinid fish in the Mojave River today. Mohave tui chubs are genetically differentiated from other tui chubs in the southern Great Basin. We found only unhybridized Arroyo chubs in the Mojave River, and unhybridized Mohave tui chubs in the refugial populations. Population substructure is evident among the four Mohave tui chub populations. Contrary to our expectation, the source population at MC Spring has significantly less genetic diversity than populations historically derived from it. Our findings suggest that a small genetically effective population size in MC Spring has reduced diversity through genetic drift in the five decades since the original transplant was made. A one-time bottleneck of 10 individuals during the founding of the Camp Cady population is evident in both reduced genetic diversity, and divergence of that population from all others. Two additional refuges, Lake Tuendae and China Lake, possess significantly higher levels of diversity. We recommend instituting artificial gene flow to rebuild genetic diversity in MC Spring and Camp Cady, and to better conserve allelic diversity in the species as a whole. New populations established in the future should be derived from Lake Tuendae and China Lake.

For the Love of a Fish

It all began during the 2003-04 school year when some of my students learned that the Mojave River watershed historically only supported one endemic fish species, the Mohave tui chub (MTC). Then they discovered, to their dismay, that it has been most likely extirpated from the river since the late 1960's and in danger of becoming extinct yet since the late 1800's, over 23 species of fish had been introduced to Mojave River system.

Two students work together during their junior and senor years to create web resource called Tui Chub Home. During the 2004-05 school year, both students attended a convocation of fishery biologists at Zyzzx, in the Mojave Desert of Southern California. During that meeting they suggested that a refugia be established on the Mojave River Campus of the Lewis Center for Educational Research. Their suggestion was included in a report published in 2004. One student conducted a habitat management experiment that took her to the California State Science Fair in 2005.

In January 2007, two year after both students had graduated from the Lewis Center's k-12 charter school, the Academy for Academic Excellence, fishery biologists with the the US Fish and Wildlife Service and the California Department of Fish and Game contacted me (Matthew Huffine) and asked if we were still interested in host a MTC refugia on the Lewis Center's Mojave River campus. By June, a site for two co-joined refugia had been identified and paperwork was being drawn up to establish a USFWS grant to aid in their development. By August, school staff and grounds workers removed 80% of the cattail and bulrush that was beginning to choke the shores of one of the refugia sites called Deppe Pond using the techniques that had been previously researched by a student. Plans were established with an existing strategic community partner, the Mojave Water Agency, to drill and develop a "minimally producing well" up to 10 acre-feet of water per year for the two planned refugia.

With the approval of the grant, $25,000 dollars, work began on October 10, 2007. As of March 12, 2008 the following actions have been taken:

October-November 2007

• Students experimented in how best capture and remove non-native species (Mosquito Fish, Gold fish and Bull Frogs) from the existing "Deppe Pond".
• Students began to collect water quality data from "Deppe Pond" and its water source (Apple Valley Ranchos Water District).
• Monitored nearby wells.

December 2007

• The long process to extirpate by non-native species from Deppe pond by first draining it to help "freeze-out" "dry-out", or displace the populations of unwanted species.

January 2008

• FMK or "For My Kids" Construction donated their time and earth moving equipment to reshape the road beds on the west side of the two refugia sites to decrease erosion into the ponds. They also dug a 294 foot long 20 foot wide, tapered 3 foot to six food deep trench that will be lined, damed at the north end and filled with well water by the fall of 2008. This site will be called "Tui Slough". It shape and dimension were inspired by the G2 seep at Larks Seep on the China Lake Navel Base in Ridgecrest.
  
• Constructed a water distribution system from the prospective well site to Deppe Pond and Tui Slough.
• WDC drilled two wells; one 120 feet deep to be used as a water source for our refugia, and the second well, 50 feet deep, to be used as a monitoring well. Both wells perforate two different aquifers.

Febuary 2008

• After visiting Bob Hilburn at the Desert Discovery Center in Barstow, California, I returned with the most of the information we needed to establish an aquarium to display the MTC to the public. I shared our undertaking with an administrator with PetSmart, and they provided us with a donation of $400 dollars in gift cards to get us started. An 36 gallon acrylic "bow front" tank and all of the supporting materials were soon purchased with this generous donation.
  
• Next, an aquarium stand was purchased to fit a location next to an existing "Waterwise Education" kiosk that is being developed for the Mojave Water Agency.
  
• The computer kiosk was next wired to the net (requiring the installation of conduit and cable). The kiosk programs and web access on this computer will be run using "KiOWARE".
  
• A web-camera and security dome was purchased and will be installed above the computer kiosk to provide 24-7 streaming video of the MTC in the new aquarium.
  

Tui Chub: Their Kin Across the Pacific North & Southwest

{Click on the above image to enlarge}

Orange→ S. isolatus clade Pink → S. bicolor clade Purple → S. mohavensis
Red → S. obesus clade Lt. Blue → no clade analysis

Next of Kin… Siphateles bicolor ssp.

{Click on the above image to enlarge}

Orange→ S. isolatus clade Pink → S. bicolor clade Purple → S. mohavensis
Red → S. obesus clade Lt. Blue → no clade analysis

Resources used to construct these maps include:

Status

• http://www.dfg.ca.gov/wildlife/species/ssc/fish.html
• http://www.nanfa.org/checklist.shtml

Maps

• http://www.biodiversity.unr.edu/data/animal/vertebrates/images/gilabico.gif
• http://www.icbemp.gov/

Locations

• http://www.desertfishes.org/cuatroc/literature/pdf/Scharpf_2005_Checklist_North_American_Fishes_Pt1.pdf

The following data came from http://www.nanfa.org/checklist.shtml.
Chub species around the Pacific Southwest (CDFG & USFWS)

• Siphateles bicolor bicolor (Girard 1856); Klamath Tui Chub
• Siphateles bicolor columbianus (Snyder 1908); Columbia Tui Chub
• Siphateles bicolor euchilus Hubbs & Miller 1972; Fish Creek Springs Tui Chub
• Siphateles bicolor eurysomas Williams & Bond 1981; Sheldon Tui Chub
• Siphateles bicolor isolatus Hubbs & Miller 1972; Independence Valley Tui Chub
• Siphateles bicolor mohavensis (Snyder 1918); Mohave Tui Chub ENDANGERED
  
• (U.S.) Siphateles bicolor newarkensis Hubbs & Miller 1972; Newark Valley Tui Chub
• Siphateles bicolor obesus (Girard 1856); Lahontan Creek Tui Chub
• Siphateles bicolor oregonensis (Snyder 1908);Oregon Lakes Tui Chub
• Siphateles bicolor pectinifer (Snyder 1917); Lahontan Lake Tui Chub
• Siphateles bicolor snyderi (Miller 1973); Owens Tui Chub ENDANGERED (U.S.)
• Siphateles bicolor thalassinus (Cope 1883); Goose Lake Tui Chub
• Siphateles bicolor vaccaceps Bills & Bond 1980; Hutton Spring Tui Chub THREATENED

1. Cow Head Tui Chub Siphateles bicolor ssp. FWS;
2. Big Smoky Valley Tui Chub Siphateles bicolor ssp;
3. Catlow Tui Chub Siphateles bicolor ssp.;
4. Dixie Valley Tui Chub Siphateles bicolor ssp;
5. Duckwater Creek Tui Chub Siphateles bicolor ssp.;
6. Eagle Lake Tui Chub Siphateles bicolor ssp.;
7. Fish Lake Valley Tui Chub Siphateles bicolor ssp.;
8. High Rock Springs Tui Chub EXTINCT Siphateles bicolor ssp.;
9. Hot Creek Valley Tui Chub Siphateles bicolor ssp.;
10. Hutton Spring Tui Chub THREATENED (U.S.) Siphateles bicolor ssp.;
11. Little Fish Lake Valley Tui Chub Siphateles bicolor ssp.;
12. Pit River Tui Chub Siphateles bicolor ssp.;
13. Rairoad Valley Tui Chub Siphateles bicolor ssp.;
14. Silver Lake Tui Chub Siphateles bicolor ssp.;
15. Summer Basin Tui Chub Siphateles bicolor ssp.;
16. Toikona Tui Chub Siphateles bicolor ssp.;
17. Warner Basin Tui Chub Siphateles bicolor ssp.;

Past Climates…

Another time but the same place… A little history… after all, living things seem to have been around for a long time!

Before North America hosted its first humans, the Great Basin and much of the Mojave resembled a farmer’s field in springtime, newly plowed and furrowed. Valleys, called basins appeared as the earth’s crust was stretched, twisted, compressed, and simultaneously lifted and dropped over time, causing the higher ground on either side to take on the appearance of mountain ranges. The resulting and “basin and range” landscape looked much like a newly plowed field. When viewed from above as in the illustrations at left, this same valley-ridge-valley-ridge landscape is still evident in many parts of the world today.

Early Landscape of the Miocene (20 millions years before the present) http://jan.ucc.nau.edu/~rcb7/20moll.jpg

This Basin and Range” landscape has been modified, however, in the numerous geologic and climatic changes of the continent in the 5-10 million years before the present time (YBP), dating back to the late Miocene Epoch (illustrated in the following image).


The last significant period of climate change introduced an ice age and the storage of water in the form of glacial ice in the northernmost latitudes, and in the ancient rising of the High Sierra [a prominent Mountain Range in Central California].

These large bodies of ice began to melt 20-15,000 YBP, during what is called the Pleistocene Era, the most recent epoch of geological history (when humans were still stone-age hunters and gatherers). The furrowed “valleys,” filled with melting snow, formed finger-shaped lakes of various sizes, connected [from time to time] by rivers or streams at the ends of the mountain ranges. Small, minnow sized fish that lived along the margins of these water bodies and waterways were some of the first to discover that these lakes connected to another at the ends of the furrow-like valleys. They joined, one to another, end to end, until they could be found across most of the entire Basin and Range land and waterscape. Eventually, the warming trend that brought about the end of the last ice age also caused the slow “de-watering” of the land- and waterscapes, drying many of the connecting rivers and streams; it brought the eventual and slow demise of the basin lakes. The populations of minnow-like fish that were once seemingly free to “go with the flow”, mixing and interbreeding, when allowed, with other populations of the same species were now isolated from one another, each in its own dwindling “water world”.

As time passed and the laws of genetics and survival of the fittest prevailed, each minnow population began to demonstrate slight changes in appearance, breeding, and feeding habits. In the late 1800’s and early 1900’s, following the Gold Rush, naturalists began to study the fish in the “Great Basin” watersheds. By the mid-1930’s, over 13 varieties of minnow-like fish had been caught, preserved and described.

Since these fish were in the same family of carps and minnows as a common sports fish in Europe called “chub” (the Cyprinidae), that name quickly stuck. However, the Paiute Indians indigenous to the Great Basin landscape on the eastern side of the Sierra Nevada called the fish the “tuipag-^I”. A major food source of this people group, the fish’s name became “Tui Chub” in honor of the Paiute nation (speculation).

With the advent of genetic techniques in the late 1980’s, the “Tui Chub” of the Great Basin and Mojave have been classified into 13+ different subspecies. The Mohave tui chub (Siphateles bicolor mohavensis) is but one of those, the only native fish to the remaining Mojave “furrow,” the Mojave River watershed.

What's the Problem Again?

The Mohave tui chub is the only known fish that is native to the Mojave River. It is believed that the demise of the tui chub in its native habitat was due to a phenomenon called “death from a thousand cuts”, inferring that many individual assaults on its existence have “ganged up” on a species over time pushing it to the fringe of its original habitat and to the edge of extinction. The forces that are believed to have created this situation include: the introduction of exotic, non-native sport fish into the waters of the Mojave River watershed, the introduction of a next of kin baitfish called the Arroyo chub, and human encroachment on the resources that the tui chub rely upon. These outside influences coupled with natural cycles that bring storms and floods mixed with periods of droughts, the tui chub has been all but eliminated from the river it once called home, endanger of the final peril for any species, extinction. The last surviving remnant of this species in the “wild” was discovered isolated from the Mojave River in a small, spring fed pool on the shore of Soda Dry Lake, an ancient inland Mojave Desert lake near Baker, California.

What’s the fuss: Why protect a species?

Every kind of living thing is connected to every other kind in some way or another, an interconnectedness known as the “web of life”. Some kinds or species in the web are like "lighthouse species," when they “wink out” they have an affect on other species in the web affecting every other species in the web, including us. Since scientists have only been studying these “webs” for less than two hundred years, there are still many unanswered questions and the loss of any species is a loss of knowledge. Scientists don't always know the role a species might play in the web or the value it might have in the future so the present generation owes their children the opportunity of discovering that role. Some argue that we should attempt to save any species endanger of extinction simply because there is no long-term imperative for not saving them. This idea can be summed up in the following quote:

"In the end, we conserve only what we love. We will love only what we understand. We will understand only what we are taught."

Baba Dioum, Senegalese poet

Saving the Mohave tui chub means saving its water supply and preserving a watersheds biological integrity. The underground aquifers that feed the Mojave River also serves all the living communities along its river valley the entire, which, beside us, supports many other organisms that are only found along its shores (snails, plants, mammals etc.).

The Mojave tui chub is an object of aesthetic beauty and a part of our natural heritage.

“Humans are a "saving" species. We like to save things that aren't always of immediate practical worth. Treasured works of art. Historic buildings. Ancient artifacts. Rare manuscripts. Family heirlooms. Why should a species and their ecosystems be any different? Isn't the Mojave tui chub a greater, far more complex creation than, say, the Mona Lisa? Humans like to build museums and protect for generations the works of other humans. Why shouldn't we do it for the works of nature, too? Ultimately, which will be more important?

“If we human beings learn to see the intricacies that bind one part of a natural system to another and then to us, we will no longer argue about the importance of wilderness protection, or over the question of saving endangered species, or how human communities must base their economic futures – not on short-term exploitation – but on long-term, sustainable development."

Gaylord Nelson, Founder of Earth Day

(Adapted for the Mojave tui chub from a quote taken from Chris Scharpf, Baltimore, about the plight of another endangered desert fish, the Devils Hole Pupfish.)

Why is the Mohave tui chub facing extinction anyway?

Exactly why the Mohave tui chub is facing extinction is unknown, however some contributing causes have been suggested. They range from natural cyclic long-term and climate change across the Mojave to the multiple impacts of human habitation in and along the Mojave River’s Watershed. In recent history, however, it is believed that human impacts (the introduction of non-native plants, amphibians, and fish to the watershed coupled with the exploitation of groundwater reserves) have had the greatest impact when coupled with the natural cycles of flooding and drought across the watershed.

At present there are added concerns about weather or not the existing gene pool within the current refugia populations is rich/broad/diverse enough support a population that can adapt to changing condition that might exist across the watershed.

“Home Sweet Home…”

Mohave tui chub seem best adapted to standing, or slow-moving, freshwater habitats. This assumption stems from limited observations made between the 1930’s and the late 60’s along the Mojave River when the Mohave tui chub could still be found in their native habitat. That said, if the chub were re-released back into the Mojave River, fishery biologists today would expect them to settle into the marshy, backwater habitats (sloughs) that support water plants and shore-side grasses along the river’s banks, if ponds or lakes could not be found.

Only one calls it home…

Since the last ice age, based on the fossil record, and observations made as early as the late 1800’s, the Mojave River (to the west of Deppe Pond and Tui Slough) and it’s watershed, pictured below, only supported one native fish, the Mojave tui chub.


With the disappearance of the large interior lakes, Mohave tui chub would naturally became dependant the deeper pools in the slower flowing sections along the Mojave River above the upper or lower Narrows (pictured at left) along with the oxbow marshes, sloughs, and pools associated with artesian springs. These features would have been more common and less disturbed prior to the 1700’s. With the arrival of western civilization from the East coast around the mid 1800’s, land, water and recreational use of the watershed’s resources slowly made survival for the Mohave tui chub, in a desert river that normally contained an erratic base flow anyway, more difficult.

Life Cycles…

The Mohave tui chub are very prolific. Chub a year and older, can “spring” into reproductive action as early as March if the water warms to above 64°F (18°C). Spawning happens in mass over vegetation. Female chub release their spawn (4,000-50,000 eggs) over water plants as males release their milt (sperm) into the water nearby. As randomly fertilized eggs become “sticky” they attach to the water plants below. Eggs are about the size of this period →. (0.1-0.4 mm), and hatch after 6-8 days at 64°- 68°F. Newly hatched chub (prolarvae) spend their first hours on the bottom before swimming to the surface. After a couple of days, young chub group themselves into “schools” thereafter. Historically, from observations as recent as the early 1930’s and 40’s, chub were frequently seen traveling in large schools along the Mojave River and its tributaries where water perennially flows above ground. Chub larger than 3 inches tend to be solitary, striking out on their own.

Food Chains…

Mohave tui chub are omnivores that “graze” on any small organism (mainly tiny crustaceans and rotifers), plant or animals (aquatic insects and their larvae, small bottom invertebrates) that drifts, floats, swims (plankton) or grows in their freshwater habitat along with organic debris (detritus) that may also collect there.

On the other hand, it important to remember that the Mohave tui chub is a food source for other fish and fish eaters (like this catfish eating a related species of chub).

Some Specifics…

The Mohave tui chub (Siphateles bicolor mohavensis, Snyder 1918) is a member of the “Barbel-lipped Minnows” or Cyprinidae family of fishes—along with carp, goldfish, dace, shiners, and squawfish. Other members of the genus Siphateles, 12 species and 13 subspecies in all, are found in water bodies throughout the Great Basin and adjacent drainages of western North America. Mohave tui chub are small, with large heads and mouths, having stocky bodies fish supported by short, soft, rounded fins that are olive to yellow-reddish-brown. Older chub sometimes develop a characteristic hump behind their heads. Chub have toothless jaws with almost rubber-like lips. Their scales are “cycloid” with smooth, circular, or concentric, lines of growth—similar to tree rings. Chub can also be recognized by the dark net-like pattern around the scales. In color, they are bright brassy-brown to dusky-olive dorsally, with side that support a fine speckling gold, and a belly that is bluish-white to silver. Their size and length seems to vary depending on water quality and quantity. For a minnow, the Mohave tui chub can be considered “mid-sized”, typically ranging between 2 and 6½ inches in length. It is hard to tell the sexes apart; however females tend to grow larger and adult, reproductive males have a prominent patch of tubercles on the top of the head behind eyes and above their pectorial fins. These tubercles could be used to initiate egg release as the male rubs his snout against the area below the female's pelvic fins. Female chubs can reach up to 8 ½ inches in length.

First Noticed by Naturalists…

In the late 1800’s and early 1900’s, following the Gold Rush, naturalists began to study the fish of the Great Basin and Mojave watersheds of Utah, Nevada, Arizona and California. By the mid-1930’s, over 13 varieties of minnow-like fish had been caught, preserved and described.

Since these newly described fish were in the same taxonomic family with carp, minnows, and a common sports fish in Europe called chub, which they resembled, that name stuck. However, the Paiute Indians, indigenous to the Great Basin landscape on the eastern side of the Sierra Nevada, called the fish the “tuipag^I”. A major food source of this people group, the fish’s name became known as the “Tui Chub” in honor of the Paiute.

With the invention of genetic techniques in the late 1980’s, the Tui Chub of the Great Basin and Mojave have been classified into 13+ different subspecies. The Mohave tui chub (Siphateles bicolor mohavensis) is but one of those, the only native fish to Mojave River valley of the Mojave River watershed.

The Forgotten Fish of an “Inconsista(e)nt River”

In 1826, Jedediah Smith, legendary trapper and explorer of the Rocky Mountains, ventured west across the deserts of the southwest in search of fur. His path followed one used by those native to the arid land that would later be called the Mojave Desert. His path crisscrossed a sandy, scrub-lined riverbed for nearly 100 miles south to the foot of a mountain range whose tributaries spawned the river. Because it mostly flowed underground, he named the dry watercourse that paralleled his trail the "Inconsistant River"(sic) on a map that later traced his westward wonderings. To this day, except for a brief stretch above and below the Upper and Lower Narrows, the waters of Mojave River still flow almost entirely underground from its headwaters at the foot of the San Bernardino Mountains to its terminus of Soda and Silver dry lakes sandwiching the small desert town of Baker. It was the more stable headwaters of Deep (see map insert) and Holcomb creeks and the West Fork of the Mojave River, that a forgotten fish, the Mohave tui chub, the river’s only native fish, called home on this "Inconsistant River".