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<br />180
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<br />CALIFORNIA FISH AND GAME
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<br />Barbour (1933) its natural range is the "Rivers of Texas, north into
<br />southern Oklahoro.a and Arkan.."8.S" ; and it is often spoken of as the soft.
<br />shelled turtle of the Rio Grande (its type locality). Sclfmidt (19241
<br />ascertained that it was plentiful near Phoenix, Arizona, in 1924, and
<br />thought it probable that it had been introduced there. Since that time
<br />it has been collected or observed at several other points in the Colorado
<br />River drainage. It is nOW known in the Colorado River from near its
<br />mouth to Pierce's Ferry in .Arizona. Linsdale, and Gressitt (Fl~i\,
<br />who may be consulted for a summary of the above records, were unable
<br />to Q.etermine ""'\Yhether this species is native in the Colorado Ri\'er or
<br />wastr.anspl!l.!!ie~there in recent years · ... .."
<br />U nfortunately~w1ii1e' doing field _workthe.a.utbQ!:,\Vas unaecl na in teJ
<br />with this evidently surprising occurrence in the Colorado, and made no
<br />attempt to question" old timers" as to the year in which they had first
<br />observed this species. However, the establishment of T,.iollYx was ~en
<br />known to many residents from Yuma to Needles who apparently con-
<br />sidered it to be native.35 The only indication that it might be a \1P'ft
<br />addition came from the remarks of a few people who said that it ",;eeffij
<br />to be increasing. "
<br />To the clarification of this lDystery the author can add b11t a feT
<br />notes. Mr. Deane Haughtelin of Winterhaven came to the rinr in 1910.
<br />In a letter of April 14, 1944, he says that he did not see or hear of soft.
<br />shelled turtles in the Colorado until ". · · shortly after "'Vi: odd
<br />War I." Mr. F. A. Thompson of Fresno, California, has recently
<br />informed me (oral communication of November 14, 1943) that he caught
<br />soft-shelled turtles in irrigation ditches (Gila drainage) near Sheldon.
<br />Greenlee County, Arizona;in 1919. Mr. Thompson is a careful obserW!
<br />and his description of the turtles fits that of Trionyx. Sheldon is ml1\:h
<br />closer to the area in which T. emoryi is native than are the other Cnlor8,!.j
<br />drainage localities from which it has been reported. The fart11est W~l-
<br />ern record for this species in the Rio Grande drainage seems to be that of
<br />Little and Keller (1937) in l\lesilla Yalley, Dona Ana County. ;\~.,
<br />Mexico. If Trionyx is not native to the Colorado drainage, it is at h'd';;
<br />flOssible that it was introduced on the upper Gila (or its tributaries\, <in,j
<br />has spread do'\Vnwards to the Colorado River from where it has pl'"~re"",,i
<br />both upstream and downstream. More intensive collecting on the I;;:'
<br />and on the Colorado above Pierce's Ferry, along with questioning of ll:t
<br />residents, should go far towards solving the problem;
<br />From the few notes taken on this turtle it may be mentio!lell t\;31,
<br />residents have described it as being quite common at Laguna Danl. au,;
<br />near Palo Verde. Specimens are found in Lake Havasu and SOTIle in ,h..
<br />area are described as reaching a weight of 25 pounds, It ,yaS n'P"rl.....
<br />that they were quite edible and that they were both trapped all.1 "h,-,t fcl
<br />food,
<br />The role of turtles in the Colorado either as compej.itors, prel1a1"r't
<br />or scavengers is unknown. but the present population is probablY \:~
<br />small to be of much significance to the fishery in these regards, (ln~:
<br />_ other hand, it maY be that the soft.sheUed turtle could be a y,l!lld'i
<br />addition to the food or sport fishery. If so, it should be given a n1ea~llrt ~
<br />
<br />.' ,car"'~.
<br />"'It shou,ld be mentioned that sOft_shelled,turtles are s~ distinctive In.~tl,\,,, ",,,,,,
<br />that there Is httle danger ot cunfusm~, them Wlt~ other turt,es, It may a,'c. ,';de""
<br />that most ot the "old timers" also be.lleved Amcwrus to be mdlgenouS-;J.;! ll.'
<br />that "it, too. has been resident In the river for many years.
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<br />FISHERY OF THE LO
<br />, ' '. ._. _ WER COLOR..~DO RIVER 181
<br />iI;<Q>d not beg,~dged "'roe inroad, _w - - - w_ - - ______c,_~~>-.."c,.c.., :
<br />"eturtles recewe any protection uo~ the .fish fauna. ~one of,.'
<br />.laws. If it is desired to mai t' n ~r. eIther the Anzona 01",.--'
<br />turtles here som l' n am an mcrease the number of ",' "
<br />ft,^;size limit ';'igbte;,'~:,:~;?~ ~onee~ing tbeir captur. .o<rld_~> -
<br />, nes would not be caught ~i e 0: t e ~ear so regulated t:na;c'--<' ".~-
<br />eetive method of takin~ tl nce rappmg wo~d probably be ';:
<br />'"':"'_".~_,_"',:'",,,,S,:hOuld be permitted. See L~~~r' 11(lo94tr3a)Pfs whIch w,ould also. ,.'..
<br />~,:: ,., or suggestIOns. .. "~-
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<br />DIRECT EFFECT OF DAMS AND DIVERSIONS
<br />ON THE FISHERY
<br />eat effects of the dams in i .' . .
<br />cussed: Tii--iddifi()Ii'lo t1~npr_~~mgeOndItlOns for aquatic life
<br />?l':~;-ve'Y dimt .ff..t, on tl:efub:~.es tbecdamsambli""""",,,
<br />
<br />---,-';;':,':','-:.:
<br />';-~:;:.,5f7:":;---::~~ .
<br />:::'2~ffi.sbing water. By backin ' d ' ",
<br />,):$as,'. ,; mOs or other depressions t~ ~~~nt~:~t:g the water
<br />it. nly at Lake Havasu ha t . g water has
<br />lFlying above 1m . I s a rue reservOIr been formed
<br />)ismall dam at H~:~~aat~~m ~~ve ~een made most produ~
<br />hing spots, At the dams t~:mse~~' ormed some bays which
<br />~. are ar'al! favo,abl. for fisbing. os (as below Laguna and
<br />
<br />~si~t() migration. Parker Dam d
<br />~~'1lP~ard migration, As far a . ~n perhaps I~perial are
<br />,S[atlOn has no detrimental effe~~~~]~~~ thhe blocklllg .or deter-
<br />.; :." .. e s ery, In this respect
<br />
<br />ob Wasteway on the AU Am'
<br />, Is a popular fishin~ sp~~~ca;,.na;ar9a12. MuUet Ba)' (foreground)
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