June 1995
Notes
PLUMMER,M. V. 1992. Relationships among mothers, litters, and neonates in diamondback water
snakes (Nerodia rhombifer). Copeia, 1992:10961098.
RAND, A. S. 1984. Clutch size in Iguana iguana in
Central Panama. Pp. 115-122, in Vertebrate ecology and systematics-a tribute to Henry S. Fitch
(R. A. Seigel, L., E. Hunt, J. L. Knight, L. Malaret, and N. L. Zuschlag, eds.). Mus. Nat. Hist.,
Univ. Kansas, Lawrence.
RAND, A. S., AND H. W. GREENE. 1982. Latitude
and climate in the phenology of reproduction in the
green iguana, Iguana iguana. Pp. 142-149, in Iguanas of the world: behavior, ecology and conservation
(G. M. Burghardt and S. Rand, eds.). Noyes Publ.,
New Jersey.
Vitt, L. J. 1978. Caloric content of lizard and snake
(Reptilia) eggs and bodies and the conversion of
weight to caloric data. J. Herpetol., 12:65-72.
VITT, L. J., ANDJ. D. CONGDON.1978. Body shape,
reproductive effort, and relative clutch mass in liz-
237
ards; resolution of a paradox. Amer. Nat., 112:595608.
WERNER,D. I. 1988. The effect of varying water
potential on body weight, yolk and fat bodies in
neonate green iguanas. Copeia, 1988:406-11.
1991. The rational use of green iguanas.
Pp. 181-201, in Neotropical wildlife use and conservation (J. G. Robinson and K. H. Redford, eds.).
Univ. Chicago Press, Chicago, Illinois.
WERNER,D. I., ANDT. J. MILLER. 1984. Artificial
nests for female green iguanas. Herpetol. Rev., 15:
57-58.
WIEWANDT,T. A. 1982. Evolution of nesting patterns in iguanine lizards. Pp. 119-141, in Iguanas
of the world: behavior, ecology and conservation
(G. M. Burghardt and S. Rand, eds.). Noyes Publ.,
New Jersey.
WILLIAMS,G. C. 1966. Adaptation and natural selection. Princeton Univ. Press, Princeton, New Jersey.
REPRODUCTIVE BIOLOGY OF THE RIO GRANDE SUCKER,
CATOSTOMUS PLEBEIUS (CYPRINIFORMES), IN A
MONTANE STREAM, NEW MEXICO
JOHN N. RINNE
United States Department of Agriculture, Forest Service,
Rocky Mountain Forest and Range Experiment Station, The Southwest Forest Science Complex,
2500 South Pineknoll Drive, Flagstaf, Arizona 86001
Although the Rio Grande sucker, Catostomus spawns in spring and, in some areas, in the fall.
plebeius, was first described almost a century and Although adults may grow to a large size (>40
a half ago by Baird and Girard (1854), Koster cm), most individuals are small and some mature
(1957) first presented the meager known life his- when only "a few inches long." Rausch (1963)
tory information for the species. It is currently examined age, growth and maturity of this suckdistributed in tributaries of the Rio Grande, pri- er. Koster (1957) suggested this species to be a
marily north of the 36th parallel (Sublette et al., good bait or forage fish and that trout can and
1990). It has been introduced into the headwaters commonly do feed on this largely primary conof the Gila River. Although substantial populasumer.
tions are extant in New Mexico, only one occurs
The Rio Grande sucker was encountered in
in Colorado. The species also currently inhabits large numbers during research investigating the
a half dozen river basins encompassing three states effects of grazing on nearstream and instream
of Mexico (Smith, 1966; Hendrickson et al., 1980; habitat and biota in the Rio de las Vacas in northSublette et al., 1990).
ern New Mexico (Rinne, 1988). Because there
Larger individuals feed on filamentous algae is a lack of ecological and life history information
and other microscopic and macroscopic organisms for Rio Grande sucker, specimens were collected
such as diatoms and benthic invertebrates inhab- between 1985 and 1987, preserved, and aspects
iting fast, rocky riffles (Sublette et al., 1990).
of their reproductive biology were examined. This
Koster (1957) reported that Rio Grande sucker paper reports information on aspects of the re-
The Southwestern Naturalist
238
1-Comparison of reproductivetraitsof male
TABLE
and female Rio Grande sucker (Catostomusplebeius)
in the Rio de las Vacas, 1985-1987. All values are
means (+SE). All comparisonsare significantlydifferent (P < 0.01).
Trait
Male
n = 112
Female
n = 99
Total length (mm1) 102.1 + 1.4 110.1 + 2.0
Fish volume (ml)
12.7 + 0.54 16.8 + 0.07
Gonad (ml)
0.82 + 0.09
0.30 + 0.02
Color index
1.5 + 0.05
1.7 + 0.04
4.6 + 0.34
Gonadal index
2.3 + 0.19
Range in total length = 60-138 mm in males, 61162 mm in females.
TABLE
2-Comparison of degreeof tuberculationon
body and fins of male and female Rio Grandesucker
(Catostomus plebeius) in the Rio de las Vacas, New
Mexico, 1985-1987. All values are means (+SE). **
= P < 0.01.
Tuberculation
Body
Head
Caudal peduncle
Gular
Operculum
Pectoralfin
Pelvic fin
Anal fin
Caudal fin
productive biology of the Rio Grande sucker inhabiting the Rio de las Vacas in Northern New
Mexico.
The Rio de las Vacas is a third-order montane
stream (elevation, 2,800 m) located on the Santa
Fe National Forest, Sandoval County, about 120
km NNW of Albuquerque, New Mexico (Rinne,
1988, 1995). Detailed descriptions of this riparian-stream area are given in Rinne (1988) and
Szaro and Rinne (1988) and are summarized here.
The stream is affected by typical forest management activities such as logging, recreation, road
building, and livestock grazing. Portions of the
study area have been fenced to exclude livestock
grazing. Riparian vegetation is more abundant
within these exclosures and is dominated by a
willow
(Salix)-alder
(Alnus) community.
Beaver
(Castorcanadense) inhabit the area, and damming
of the stream is common, however dams are not
permanent because of annual washouts by spring
runoff. Streambanks are unstable in the grazed
areas (Rinne, in litt.) and fine sediment content
of the stream substrate is greater in reaches subjected to grazing (Rinne, 1988).
Most Rio Grande suckers were collected during annual summer sampling (June to July), with
additional samples taken in March, April, September, and October 1985. Rio Grande sucker
were stunned with a direct current, backpack
electrofisher, dipnetted, and immediately preserved in 10% formalin-sugar solution in order
to enhance color retention in specimens. The total
length (TL) of preserved specimens was measured and fish volume was estimated by liquid
displacement (ml). Gonads were then removed
and their volumes similarly determined by liquid
vol. 40, no. 2
Male
Female
n = 112
n = 99
2.7
2.5
2.9
2.6
2.6
2.4
0.05
0.07**
0.03
0.05**
0.07
0.07**
3.0
3.0
+
+
+
+
+
+
3.0
3.0
3.0 + 0.02**
3.0
3.0 + 0.01**
3.0
3.0 + 0.02**
3.0
3.0
3.0
displacement. Gonadal indices (GI) were calculated by dividing gonadal volume by fish volume
and multiplying the resulting value by 100. Fecundity was estimated by removal of ovaries and
counting of all mature ova present in 21 females
collected in March, June, and July, 1985 and
with GI greater than 4.0.
Presence and intensity of tuberculation and
breeding coloration on the body and fins were
noted relative to sex. Variation in tuberculation
was coded from 1 to 3 to delineate either pronounced presence (1), weak presence (2), or absence (3). Color was recorded as either present
(1) or absent (2).
Data on reproductive traits between sexes were
analyzed by simple t-tests. Analysis of variance
(ANOVA) was used to compare GI among sample dates. Length and GI were related by regression analyses to depict size at maturity.
Of the 211 suckers collected for reproductive
analyses during the period March 1985 through
June 1987, 112 were males and 99 females. Female suckers were only slightly but significantly
(P = 0.002) larger than males (Table 1). Sexual
dimorphism was also illustrated by the significantly greater mean volume of female than male
suckers (Table 1).
As in most cypriniform fishes, the presence of
color was also significantly more common in males
than in females (P < 0.001). Regression models
for the sexes explained only about 25% of the
variation in color of suckers. By comparison, logistic regression produced a "best fit" model that
included sex, month, gonad volume, and length.
239
Notes
June 1995
TABLE3-Comparison of mean seasonalgonadalindicesof Rio Grandesuckers(Catostomus
plebeius)in the
Rio de las Vacas, New Mexico, 1985-1987.
Sample date
Male
March'
n=
April
n=
June
June
July
Sept
Oct
n
n
n
n
n
=
=
=
=
=
5 2.12 +
3 1.8 +
20 4.07 +
13 0.57 +
35 3.13 +
23 0.72 +
13 2.18 +
Female
1.43
n = 14 4.26 + 0.32
0.31
n=
0.43
0.19
0.19
0.13
0.72
n
n
n
n
n
=
=
=
=
=
83.83 + 0.51
18
20
15
6
18
7.80
2.69
5.69
3.18
3.61
+
+
+
+
+
1.12
0.58
1.03
0.30
0.18
' All samplesmade in 1985 except for the secondsamplelisted for June and the samplein September,which
were made in 1987.
The remaining independent variable, fish volume, was not significantly (P = 0.09) related to
color. The fitted model for Rio Grande suckers
in the Rio de las Vacas is:
E (the logit) = -7.0199
- 0.8614(sex)
+ 0.3829(month)
+ 0.7869(gonad volume)
+ 0.0313(length)
where the probability of no color is: expected E/1
+ expected E. This model predicted color correctly 68.7% of the time or in 145 of 211 specimens. Separation of sexes and similar analyses
resulted in increased predictability of color for
females (81 of 99 or 81.8%).
In general, differences in tuberculation on the
body and most fins of male versus female suckers
was not as marked as was coloration (Table 2).
However, the head, gular region, and pectoral
fins of male suckers contained greatly pronounced
tuberculation compared to female suckers.
Typical of most cypriniform fishes, GI during
the spawning season were significantly greater (P
< 0.001) in female than in male suckers (Table
1). ANOVA indicated significant differences (P
= 0.001) in gonadal indices among sample dates
for both males and females (Table 3). Assuming
greater indices indicated increased reproductive
activity, Rio Grande suckers displayed a spawning peak in early summer, (June through July).
Gonadal indices were significantly greater in
suckers in June 1985 than in June 1987. If one
uses greater indices (i.e., >4.0) as an indication
of maturity, suckers reach maturity at about 90
mm, TL (Fig. 1).
Fecundity of the 21 female suckers (>100 mm,
and GI > 4.0) ranged from 695 to 4,701 ova,
and averaged 2,035 + 240 (SE). Regression anal-
yses indicated 56% of the variation in fecundity
of suckers was explained by gonad volume. Fecundity of suckers varied significantly with season
(P = 0.02) and was greatest in the autumn and
least in the spring.
Koster (1957) previously suggested that the
Rio Grande sucker displayed a definite spring to
early summer and perhaps an autumnal spawning effort. This native sucker definitely spawned
in the spring and early summer, but an autumnal
spawn was not evident. Descriptions of timing of
spawning of other members of the genus Catostomus in the literature are varied. The desert
sucker, Catostomusclarki, has been described as
spawning in the spring within its geographic range
(Smith, 1966) and late winter to early spring in
Arizona (Minckley, 1973), and in late winter in
the Santa Clara River, Utah (Rinne, 1971). Cross
(1975) suggested a prolonged period of spawning
(March to June) for the desert sucker in the
Virgin River, Nevada. Although they did not specifically observe this, Sigler and Miller (1963)
indicated the flannelmouth sucker, Catostomuslatipinnis, appears to spawn in spring and summer
in the upper Colorado River.
Variability in spawning season of western catostomids may be explained by differences in water temperature and stream size, and perhaps
most importantly, pattern of season or annual
runoff. Based on annual observations of flows in
the Rio de las Vacas, the Rio Grande sucker
spawned on the waning side of the period of peak
spring flows. Once normal spring runoff subsided
(i.e., late June to early July), spawning quickly
terminated (Table 3). This is further illustrated
by the June 1985 and 1987 samples. Time of
sampling in 1985 was June 6. By comparison,
sampling in 1987 was almost 3 weeks later (June
240
The Southwestern Naturalist
vol. 40, no. 2
18
24). By late June 1987, flows had abated and GI
were significantly lower than two years previous.
15
This is attributable to presence of more spent
females and males and was also noted for Rio
S12
12
*
Grande chubs in this same stream (Rinne, 1995).
Greenfield et al. (1970) recorded protracted <- 9 spawning (March-July) for the Santa Anna
sucker, Catostomussantaanae, in California; how- 86 6
ever, peak spawning was during May and June.
"~7------------~
3
Similarly, Deacon and Minckley (1975) documented extended spawning (December to perhaps July) for C. clarki in Aravaipa Creek, Ar60
80
100
120
140
180
160
izona.
TOTAL
LENGTH
INMLLIMETERS
Breeding colors were more often present in
FIG. 1--Regression of gonad index on total length
male than in female Rio Grande suckers. Greater of suckers
to delimitprobablesize at maturity.Dashed
coloration in male Rio Grande suckers may be lines are 95%confidencelimits of meansfor both fitted
important for females to locate, attract, and stim- (lower two) and predicted(upper) regressionlines.
ulate males in the spawning act during more turbid conditions of spring runoff resulting from
increased suspended sediment. Orange-red stripes because of hybridization with the white sucker,
are present in both sexes of the desert sucker C. commersoni.There is a need for a comprehen(Smith, 1966). Color was more common and pro- sive status survey of the Rio Grande sucker to
nounced in the spring than in summer or in the enable managers to more effectively assess stratautumn.
egies for management and perhaps insure susTuberculation was present in both male and tainability of natural populations in the wild.
female suckers, but was more pronounced in the Such a survey is underway through a cooperative
males, primarily on the head and gular region effort by New Mexico State University and Unit(Table 2). Tuberculation has been described as ed States Forest Service research, Flagstaff, Aribeing most developed in male bluehead suckers, zona.
C. discobolus(Miller and Hubbs, 1960), and only
Additional reproductive information is needed
on the Rio Grande sucker in other streams within
in ripe male flannelmouth suckers (Cross, 1975).
In summary, reproductive activity and traits of its range in New Mexico. Because color develthe Rio Grande sucker in Rio de las Vacas par- opment was significantly related to time, more
alleled the variability described in the literature intensive sampling (weekly or biweekly) during
for congeners. To date, most of the information spawning peaks and further analyses of color,
on the genus has been qualitative and descriptive fecundity, GI, and maturation of ova are needed
and not as detailed as that reported by Andreasen to substantiate whether spawning is unimodal or
and Barnes (1975) for the Great Basin region. bimodal in pattern. In addition, its interactions
Such a lack of biological studies results, in part, with other members of both the native fish comfrom the erroneous concept that suckers are "rough munity (e.g., longnose dace (Rhinichthys cataracfish" and are "harmful" to other species, es- tae), Rio Grande Chub (Gila pandora) and the
pecially trout (Holey et al., 1979). Indeed, suck- native Rio Grande cutthroat trout (Oncorhynchus
ers more probably are a source of food for intro- clarki virginalis)) and the introduced portion of
the community (e.g., brown (Salmo trutta), brook
duced and native salmonid species.
Even suckers (e.g., Cui-ui, Chasmistes cujas, (Salvelinus fontinalis), and rainbow (Oncorhynand Sonora C. insignis and desert C. clarki suck- chus mykiss) trouts) need documentation.
ers) can become endangered and candidate species
LITERATURE
CITED
as a result of human activities. Biological information on these species is necessary to manage
ANDREASEN,
J. K., AND J. R. BARNES. 1975. Rethese species and prevent their extinction. Rio
ardensand C.
productivelife historyof Catostomus
Grande suckers are reported to be almost extirdiscobolus
in the Weber River,Utah. Copeia, 1975:
643-648.
pated from Colorado, and are steadily disappearing from streams in New Mexico, largely BAIRD,S. F., ANDC. GIRARD. 1854. Descriptions of
c:P
June 1995
241
Notes
new species of fishes collected in Texas, New Mexico, and Sonora, by Mr. John H. Clark, on the
United States and Mexico boundary survey, and in
Texas by Capt. Van Vliet, U.S.A., Second part.
Proc. Acad. Nat. Sci. Phila. 7:24-29.
CROSS,J. N. 1975. Ecological distribution of the
fishes of the Virgin River (Utah, Arizona, Nevada).
West. Interst. Comm. Higher Ed., Boulder, Colorado.
DEACON,J. E., ANDW. L. MINCKLEY.1975. Desert
fishes. Pp. 166-179, in Desert biology (G. W.
Brown, ed.). Vol 11:385-488, Academic Press, New
York.
GREENFIELD,
D. W., S. T. Ross, ANDG. D. DECKERT.
1970. Some aspects of the life history of the Santa
Ana sucker, Catostomus santaanae (Snyder). California Fish and Game, 56:166-179.
HENDRICKSON,
D. A., W. L. MINCKLEY,R. R. MILLER,D. J. SIEBERT, AND P. H. MINCKLEY.1980.
Fishes of the Rio Yaqui Basin, Mexico and the
United States. J. Ariz-Nev. Acad. Sci. 15(3):65106.
HOLEY, M., B. HOLLENDER, M. IMHOF, R. JESIEN,
R. KONOPACKY,M. TONEYS, AND D. COBLE. 1979.
"Never give a sucker an even break." Fisheries,
4:2-6.
KOSTER,W. J. 1957. Guide to the fishes of New
Mexico. Univ. New Mexico Press, Albuquerque.
MILLER,R. R., ANDC. L. HUBBS. 1960. The spinyrayed cyprinid fishes (Plagopterini) of the Colorado
River system in western North America. Misc. Publ.
Mus. Zool., Univ. Michigan, 115:1-39.
MINCKLEY,
W. L. 1973. Fishes of Arizona. Arizona
Game and Fish Dept., Phoenix.
RAUSCH,R. R. 1963. Age and growth of the Rio
Grande mountain-sucker, Pantosteusplebeius (Baird
and Girard). Unpubl. M.S. thesis, Univ. of New
Mexico, Albuquerque.
RINNE,J. N. 1988. Grazing effects on stream habitat
and fishes: research design considerations. N. Amer.
Jour. Fish. Mgmt., 8:240-247.
1995. Reproductive biology of the Rio Grande chub, Gila pandora (Teleosotomi: Cypriniformes) in a montane stream, New Mexico. Southwestern Nat., 40(1):107-110.
RINNE,W. E. 1971. The life history of Lepidomeda
mollispinis mollispinis (the Virgin River spinedace)
a unique western cyprinid. Unpubl. M.S. thesis,
Univ. of Nevada, Las Vegas.
SIGLER, W. F., AND R. R. MILLER.
1963.
Fishes of
Utah. Utah Dept. Fish and Game, Salt Lake City.
SMITH, G. R. 1966. Distribution and evolution of
the North American catostomid fishes of the subgenus Pantosteus, genus Catostomus. Misc. Publ.
Mus. of Zool., Univ. Michigan, 29:1-132.
SUBLETTE, J. E., M. D. HATCH, AND M. SUBLETTE.
1990. The fishes of New Mexico. Univ. of New
Mexico Press, Albuquerque.
SZARO,R. C., AND J. N. RINNE. 1988. Ecosystem
approach to management of southwestern riparian
communities. Trans. 53rd N. Amer. Wildl. and
Nat. Res. Conf., 53:502-511.
MARKING OTOLITHS IN RAZORBACK SUCKER EMBRYOS AND
LARVAE WITH FLUORESCENT CHEMICALS
ROBERT T. MUTH AND STEVEN M. MEISMER
Larval Fish Laboratory,Department of Fishery and Wildlife Biology,
ColoradoState University, Fort Collins, CO 80523
Efforts to recover the endangered razorback
sucker (Xyrauchen texanus) include hatchery
propagation of fish for reintroduction and research projects, documentation of reproduction
and recruitment in the wild, and evaluation of
reasons for low recruitment and ways to improve
survival of young fish. Minckley et al. (1991)
recommended marking hatchery-produced razorback sucker to distinguish them from fish produced naturally. Because razorback sucker are
sometimes stocked in large numbers as larvae or
small juveniles, a mass-marking technique applicable to early life stages is required. The mark-
ing technique could also be used in field markrecapture studies to facilitate investigation of the
early biology of razorback sucker and fate of reintroduced fish.
Marking otoliths of fish has great potential for
use in stock identification, assessment of stocking
success, and life-history
studies (Brothers,
1990;
Buckley and Blankenship, 1990). One technique
for rapid mass marking is incorporation of fluorescent chemicals in otoliths by immersion of fish
embryos or larvae in solutions of these chemicals.
Two compounds proven effective for this technique are alizarin complexone (ALC) and tet-