STATUS UPDATE, JANUARY 2004
University of Wisconsin Zoological Museum, Madison
From January 7-17, 2004, I participated in scientific
fish surveys in springs, streams, and rivers over a broad area of central
México. This fieldwork had
multiple objectives and focused on a variety of species, including
catostomids (suckers of the genus Scartomyzon),
cyprinids (minnows of the genus Aztecula,
Algansea, Hybopsis, and Yuriria),
lampreys (Lampetra geminis), and
goodeids. Here I summarize
the observations made on goodeids.
Lago Mayor, Chapultepec Park, México, D.F.
I arrived in Mexico City late on 7 January, and the
next morning Norman Mercado-Silva, from the University of
Wisconsin-Madison, and Andrés Martínez-Aquino, from the Universidad
Nacional Autónoma de México (UNAM), México, D.F., and I sampled a small
lake in Chapultepec Park in Mexico City for Girardinichthys
viviparus. This goodeid
is endemic to the Valle de México, the endorheic (no natural outlet)
basin where Mexico City is located. Girardinichthys
viviparus is critically endangered, and is currently known from only
three areas, the lakes of Chapultepec Park, Lago de Xochimilco, located on
the southern edge of Mexico City, and a small spring tributary to the Río
Tula in the adjacent state of Hidalgo, north of the Valle de México.
The Lago de Xochimilco and Río Tula spring
populations of G. viviparus are
apparently small, whereas the size of the Chapultepec population is
unknown. Lago de Xochimilco
is one of the last remnants of the extensive shallow natural lakes that
once covered much of the Valle de México.
The lake is heavily modified and polluted, with limited fish life.
However, over the last 15 years there have been increasing efforts
to restore the environmental quality of this lake.
The Río Tula spring population of G.
viviparus is outside the native range of the species and appears to be
from a relatively recent colonization.
In the late 1800s a canal was constructed between the Valle de México
and the Río Tula (which is part of the Río Pánuco basin flowing into
the Gulf of Mexico) to drain the lakes in the Valle de México.
Girardinichthys viviparus presumably used this canal to reach the
spring sometime within the last 100 years.
The Río Tula now carries large volumes of poorly treated sewage
and industrial wastes and does not support fish life, so the spring
population is effectively isolated from the Valle de México.
Chapultepec Park is a large and beautiful park in the
heart of México City, somewhat reminiscent of Central Park in New York
City. It has a number of
small “lakes” (=ponds), each a few hectares in size.
They all appear to be artificial, with steep, concrete lined sides
and canals and pumps to control their water levels. However, they may well be located at the sites of former
natural ponds or wetlands. The
water quality in each is poor. Their
steep, slippery sides make fish sampling difficult.
We were able to sample fish from the largest lake,
Lago Mayor, located across the street from the famous National
Anthropological Museum (19 25’ 21.1” N; 99 11’ 2.7” W).
This lake has a boat rental area, and here the water is shallow
enough to pull a seine. We
made two short seine hauls, covering about 50 m2 total, and
captured well over 150 G. viviparus
, plus about 100 Goodea atripinnis.
We also collected several individuals of G.
viviparus in a trap made from a 1-liter soda bottle with a hole cut in
the side and baited with bread. This
type of trap is commonly used by kids to capture goodeids from the
Chapultepec Park lakes; many captured fish are kept as pets or eaten.
Most of the G. viviparus
we caught had distended abdomens full of parasitic worms.
The population in Lago Mayor appears to be relatively
large, despite the artificial habitat conditions, poor water quality, and
heavy parasite burden. This
is encouraging given the rarity of the species.
However, the Chapultepec population occupies a small isolated
habitat and is hardly secure. It
could be quickly decimated or even eliminated if, for example, the lakes
were drained for repair.
La Mintzita springs, Michoacán
After we sampled Lago Mayor, we were joined by Guillermina Cabañas-Carranza from UNAM and Dr. Hank Bart and Mark Clements from Tulane University, New Orleans, and we began the expedition in earnest. We left Mexico City that evening and headed west to Morelia. We arrived there late on 9 January, after sampling two non-goodeid sites along the way. On the 10th we met with Professor Martina Medina-Nava from the Universidad Michoacana de San Nícolas de Hidalgo (UMSNH), Morelia, and three of her students. Together, we first sampled the Río San Marcos, Michoacán, in a small wooded canyon below the falls of Chiquimitio (19 47’ 56.4” N; 101 14’ 45.9” W) for the native catostomid Scartomyzon austrinus and the native lamprey Lampetra geminis. This stream was not really suitable goodeid habitat, being 5 m wide, 0.5-1.2 m deep with a cobble/gravel and boulder bottom and a very steep channel with fast currents. However, in 120 m of electroshocking we did catch 5 specimens of the goodeid Goodea atripinnis, along with 18 L. geminis, 60 S. austrinus, and 7 Aztecula sallei (Cyprindae, native). After a late lunch, we met briefly with Professor Omar Domínguez-Domínguez, who is in charge of the goodeid conservation and captive maintenance facility at UMSNH. Then, as the afternoon waned, we visited the La Mintzita springs about 20 km southwest of Morelia (19 38’ 52.3” N; 101 16’ 13.0” W), one of the most important remaining goodeid habitats in central México.
La Mintzita is a marshy spring –fed lake that drains
into the Río Grande de Morelia and hence into Lago Cuitzeo.
The Río Grande de Morelia/Cuitzeo basin is endorheic, although its
fauna indicates that it was once connected to the adjacent Río Lerma
basin. Most of the Río
Grande de Morelia/Cuitzeo system has been greatly degraded, and La
Mintzita is one of the last remaining high-quality sites in the basin.
A few hundred meters below the lake the outlet canal receives
wastes from a large paper mill and no longer has the capability to support
fish life, so La Mintzita is isolated from other fish populations in the
We sampled the outlet canal just below the lake with a
backpack electroshocker and the lake itself just above the outlet with a
seine. The canal was about
8-m wide and 0.5-1.0 m deep with a fast strong current and gravel bottom.
In 80 m of sampling we collected the following goodeids: 3 Alloophrous
robustus, 30 Goodea atripinnis,
about 100 Xenotoca variatia, 5 Skiffia
lermae, and about 15 Zoogoneticus
quitzeoensis . We also
caught 10 Poeciliopsis infans (Poeciliidae; native) and about 25 Xiphophorus
helleri (an exotic Poeciliid), plus 10 Yuriria
alta (Cyprinidae; native) and 10 Scartomyzon
austrinus. We then pulled
the seine for about over about 300 m2 in the lake, which
averaged about 1-m deep with a sand and clay bottom and clear water at
15-19 C temperature. We
captured 3 A. robustus, 5 G. atripinnis,
30 X. variata, about 100 S.
lermae, 3 Z. quitzeoensis, plus at least 1000 P. infans, 5 X. helleri,
and 30 Y. alta.
The S. lermae males were
particularly beautifully colored, but unfortunately by the time we
finished processing our samples it was too dark for photos.
lermae is endangered and A. robustus and Z.
quitzeoensis are uncommon, and La Mintzita is one of their last
strongholds, whereas Goodea
atripinnis and X. variata
are widespread and common in central México.
La Mintzita remains in good condition, but its future is uncertain.
Settlement and use of the
adjacent lands around the lake have increased in the last 10 years, as has
runoff of domestic wastes into the lake.
More ominously, the city of Morelia is considering pumping water
from the lake for municipal uses, which could reduce the lake level and
perhaps even eliminate the springs that feed the lake, thus destroying
this unique goodeid habitat. Martina
and her students are working to help protect the lake.
Ameca basin, Jalisco
We were on a tight schedule, so as darkness fell, we made our goodbyes with Martina and her students and drove west to Guadalajara, arriving there late that night. The next morning, the 11th, we headed west from Guadalajara into the Ameca basin, which drains to the Pacific, to look for Allodontichthys polylepis (critically endangered) and Allotoca goslinei (endangered) and Scartomyzon mascotae. We first visited the Río de la Pola at the Highway 70 crossing near Estanzuela, about 40 km west of the city of Ameca (20 31’ 27.7” N; 104 20’ 12.0” W), one of the three sites from which A. polylepis has been taken. Here the river was about 8 m wide with long pools from 0.8-2.0 m deep connected by short shallow riffles (see photo). The bottom was gravel/cobble, bedrock, and sand, and the surrounding landscape was open dry scrub. I first visited this site on 23 August 1997 and in 70 m of electoshocking took 10 A. polylepis, 48 Ilyodon furcidens, 2 Scartomyzon mascotae, and 4 Tilapia (an exotic cichlid). My next visit, on 9 February 2000, was less productive, and in 300 m of electofishing I took only 90 I. furcidens and 10 S. mascotae. However, this year’s trip had the lowest yield of all, with only 10 I. furcidens, 2 Tilapia, and 15 Cyprinus carpio (common carp, an exotic cyprinid) in 90 m of shocking. I’m doubtful that A. polylepis still remains at this site. The reason for the disappearance of A. polylepis is unclear. The site had no obvious major pollution or habitat modifications. However, on my last two visits the flow was very low, providing little of the riffle habitat that A. polylepis needs. Perhaps flows during recent dry seasons were insufficient to support A. polylepis.
|DE LA POLA
|We next moved to the Arroyo Diabolos about 10 km N of
the Río de la Pola, to which it is a tributary. We sampled at the crossing on the road to Guachinango (20
33’ 25.4” N; 104 21’ 33.9” W).
This site flowed through a narrow canyon.
The creek itself was abut 3 m wide, deep slow bedrock pools up to 2
m deep connected by short shallow gravel riffles .
On my first visit here, on 9 February 2000, I electroshocked 75 m
and took 10 A. polylepis, 152 I.
furcidens, and 8 Tilapia. The A.
polylepis came out of the deep pools, an atypical habitat, probably
because little of their preferred riffle habitat was deep enough to
support fish. On this
trip’s visit we shocked 100 m, but caught no fish of any kind.
The absence of fish was perplexing.
No pollution was evident and the habitat conditions looked similar
to those in 2000. However, as
I have speculated for the Río de la Pola site, perhaps flows during
recent dry seasons were so low that the fish populations were eliminated.
Whatever the reason, A.
polylepis no longer occurred at this site.
We then moved west to the Río Atenguillo at Highway
70 near the town of Atenguillo (20 25” 54.6” N; 104 28’ 56.4” W).
The Río de la Pola is a tributary to this river.
The Río Atenguillo was much larger than the other sites with a
width of about 25 m and a strong flow.
It had numerous riffles that looked ideal for A.
although we shocked 100 m and captured a variety of fishes, we collected
no goodeids. In my one
previous visit to this river (at a site further upstream) I also did not
take any goodeids, nor did other ichthyologists in earlier visits to this
Finally, we moved east to the Arroyo Potrero Grande,
on Highway 70 about 10 km west of Ameca (20 31’ 17.2” N; 104 7’
29.2” W). This is the third
and final site from which A.
polylepis has been taken, as well as the only site from which Allotoca
goslinei has been found in the last 20 years. The creek here was only 1-2 m wide, with a maximum depth of
0.4 m, small rocky pools and very shallow riffles, and limited flows.
The banks were heavily wooded.
was taken here as recently as 1996 by Derek Lambert, but I did not see the
species in my only previous visit on 10 February 2000 nor on this year’s
visit. On both of my visits flows were so low that there was no
suitable riffle habitat for A.
goslinei has declined dramatically in abundance at this site
over the last four years. During
my 2000 visit A. goslinei was
common. In 200 m of shocking
99 A. goslinei, 6 I. furcidens, and 28 Scartomyzon
mascotae were collected. However,
during this year’s visit only 7 A.
goslinei were taken in 200 m of shocking, as well as 19 I.
furcidens, 17 S. austrinus, and about 120 Xiphophorus
helleri (an exotic). The
appearance of X. helleri may
account for the decline in A.
goslinei; both occupy the same pool habitat and are potential
The complete absence of A. polylepis from its three known localities and the major decline
in A goslinei abundance at its
one remaining locality indicate that the future of these two species in
the wild is precarious. It is
too early to conclude that A.
polylepis is extinct in nature or that A.
goslinei is doomed, as large areas of potential habitat for both
species have not yet been surveyed. During
my next visit to this area I hope to survey the Río Ameca downstream from
where the Arroyo Potrero Grande enters it.
This area is badly polluted from the city of Ameca, but it once
supported A. goslinei and possibly A.
polylepis as well. Perhaps
individuals of one or both species still persist in poorly accessible
areas far downstream from Ameca where the pollution has somewhat
dissipated. However, even if A. goslinei and A. polylepis
are found in the Río Ameca, their native habitat appears to be
deteriorating, and it is critical that captive populations of both species
be maintained and expanded.
Springs around Durango
We spent the night of 11 January back in Guadalajara
and then left on the 12th for the city of Durango, far to the
north. We sampled two
non-goodeid sites on the way and arrived in Durango very late that night.
The next morning we began sampling sites in the Río Mezquital
system around Durango, looking for Scartomyzon milleri and goodeids in the genus Characodon.
was widespread and common in springs in the Río Mezquital system just
north and west of the city of Durango.
In a morphological analysis of the genus, Smith and Miller (1986;
American Museum Novitates 2851:1-14) described C.
audax from a spring near the town of El Toboso.
They attributed all other populations in the region around Durango
to C. lateralis, a species
described by Gunther in 1866 for which the type locality is unknown (erroneously
listed as “Central America” in the original description). However, recent genetic analyses by Omar Domínguez and
colleagues (Doadrio and Domínguez. 2003.
Molecular Phylogenetics and Evolution, in press) indicate that the
taxonomic situation is more complex, and call into question the current
definition and distribution of both C.
audax and C. lateralis.
Regardless of how they are defined, both C.
audax and C. lateralis are in trouble. The
Río Mezquital system has been highly degraded by pollution, excessive
water withdrawls, and exotic species. Only 6 or 7 Characodon
populations remain extant, each isolated in a small spring.
Both species are considered critically endangered.
The weather, which had already been unusually cold and
rainy, became notably bad when we arrived in Durango, with temperatures of
only 5-12 C and steady (and at times heavy) rain. There was talk of snow.
Every site was dreary and muddy.
We spent most of 13 January at non-goodeid sites, but ended the
afternoon sampling the El Toboso and Abraham Gonzales springs for Characodon.
The El Toboso spring, known as “El Ojo de Agua de
las Mujeres”, is located in an open scrubby, stony, and normally arid (but
quite wet this trip) landscape about 200 m north of the town of El Toboso
(24 16’ 30.7” N; 104 34’ 52.8” W).
The spring had been impounded by a stone wall to form a small pond
(see photo) and contained numerous aquatic plants.
It is the type locality of Characodon
audax, which we found to be common among the plants.
We quickly took about 40 with a few swipes of our dip nets and
short pulls of the seine. The
specimens were beautiful with black fins and dark iridescent flanks (see
photo), and some of the males had reddish ventral areas, although poor
light and steady rain made it difficult to get a good photo.
|As we walked back into El Toboso after sampling the
spring, we encountered some friendly (and a bit drunk) locals, who asked
what we were fishing for. In
subsequent conversation they told of how catfish had recently been stocked
into the El Toboso spring for aquaculture purposes, on the advice of the
state government agricultural agency.
They also said that catfish, largemouth bass, tilapia, common carp,
and perhaps other species had been stocked into the Abraham Gonzales
springs 10 km to the south, our next destination.
This was unwelcome news since several of these species, if
established in the springs, could harm the Characodon
populations. Catfish and bass
are predators that could eat Characodon,
and common carp might uproot and eliminate aquatic plant habitat.
We proceeded to the town of Abraham Gonzalez.
The springs there originate in a series of marshy ponds on the east
side of town, and their outflow is passes through the middle of town via a
narrow concrete lined channel. We sampled this channel with dip nets just as it left the
ponds (24 12’ 50.7” N; 104 31’ 47.8” W).
At least some of the springs were thermal; the channel was 24-27 C
despite an air temperature of only 9-10 C.
The channel had little habitat but was nonetheless full of fish. In about 25 m we collected about 50 Characodon, over 100 Gambusia
senilis (an exotic Poecilid), 7 of the native pupfish (Cyprinodontidae)
Cyprinodon meeki, and about 50 Tilapia. The Characodon here
looked generally similar to El Toboso, although they were not quite as
dark (see photo). Failing
light and rain made photography difficult.
We spent the night in Durango and the following morning sampling non-goodeid sites, before heading towards the city of León, far to the south and east. Along the way, about 70 km southeast of Durango, we sampled for Characodon at the springs in the town of Amado Nervo. Our site was in an open grove of cypress trees on the south edge of town just north of Highway 45 (23 50’ 33.2” N; 104 11’ 12.1” W). Here a series of small springs entered a small (< 1 m wide, 0.3 m deep) stream that drained the town. Using dip nets, we collected about 30 Characodon and 1 Tilapia in 25 m of sampling. These fish were much lighter in color than the El Toboso or Abraham Gonzales specimens, and had dark spots/blotches on the sides and a faint reddish cast to their abdomen (see photo). Their appearance matched the description of C. lateralis.
Río Duero, Michoacán
Río Duero, Michoacán
We left Amado Nervo near dusk and arrived in León at
about 2:30 a.m. I had
developed a stomach illness that afternoon, so it was a long ride, and I
was never so happy to collapse into bed.
The following morning, 15 January, I felt better and we headed
south towards the Río Duero to look for Scartomyzon
austrinus and Lampetra geminis.
On the way we briefly sampled the Río Turbio, Guanajuato, a Río
Lerma tributary, at the Highway 41 crossing (20 43’ 15.3” N; 101 42’
15.7” W). In the late 1960s
this site had supported at least three goodeids and a variety of other
fishes, but now it was polluted and we caught no fish.
We arrived at the Río Duero, another Río Lerma
tributary, in mid afternoon, and sampled at the crossing on the road to Etúcuaro
(19 53’ 3.6” N; 102 8’ 53.9” W).
I had visited this site previously, on 7 November 1991, and taken a
number of L. geminis, S.
austrinus and Algansea tincella (a native cyprinid), but for goodeids only a
single Goodea atripinnis.
Elsewhere in the Duero system I had done much better, catching a
few Alloophorus robustus and
many G. atripinnis, Skiffia
multipunctata (endangered) and Zoogoneticus
quitzeoensis. However, on
this year’s trip the goodeid yield from the Etúcuaro site was much
We began by electrofishing some narrow (1-2 m), deep
(1-1.5 m), clear spring channels that entered the river just above the
bridge. I had been unaware of
these channels on my previous visit.
Fish density was low in the channels, but diversity was high.
For goodeids, we took a single Allotoca
dugesi (endangered), to my knowledge the first record of this species
from the Duero system, 2 S.
multipunctata, and 2 Z.
quitzeoensis. The male S.
multipunctata were particularly attractively colored.
We also took 3 L. geminis and 3 A. tincella.
We then moved out into the river proper, which was 8 m wide and
1-1.5 m deep, with a clay and gravel bottom.
It was surrounded by agricultural lands and was swollen with muddy
irrigation runoff. The strong
currents made sampling difficult. In 120 m of shocking we collected 7 more S. multipunctata plus 11 L.
geminis, 7 S. austrinus, and
13 A. tincella.
With completion of the sampling of the Río Duero, our
fieldwork was over. We packed
up and made the long drive to Mexico City, arriving, as had become our
habit, long after midnight. The
next day we organized gear, packaged specimens, bought souvenirs for our
families, and visited with friends before returning to our homes on 17
Our trip yielded both encouraging and discouraging
results concerning goodeids. On
the positive side, Girardinichthys
viviparus persisted in
Chapultepec Park, La Mintzita continued to provide a home to five goodeid
species, Characodon hung on in a
few springs near Durango, and the Río Duero remained a refuge for at
least three goodeid species. On
the negative side, we could not find any Allodontichthys
polylepis within its known range, the single remaining population of Allotoca goslinei had decline precipitously, and the La Mintzita and
Durango springs faced imminent environmental threats.
The future does not look promising for most goodeids in central México.
Protection of those sites that still support goodeids and other
native species must be a top conservation priority.
Concurrently, captive populations of all goodeids species must be
maintained and expanded, since the survival of many wild populations is in