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By David E. Boruchowitz
Central American lakes like Lake Nicaragua have a unique fascination. Some of our favorite small cichlids live there, as do large predators like the wolf cichlid (Parachromis dovii), not to mention the toothsome crocodilians and full-grown bull sharks on freshwater vacations. You can create a very interesting (if rough-house) biotope community around such a habitat—without the man-eating capabilities.
For this one we’re going to use a 6-foot tank, 18 inches wide, either the 100-gallon or one of the taller versions, like the 125. Substrate is a couple inches of natural gravel, and the bottom is broken up into visual territories with various rock piles, pieces of driftwood, etc. Caves and overhangs are important, since the cichlids we’re going to use are cave-dwelling and territorial. The 9 square feet of bottom area gives us the potential for three territories if all goes well, so make it look like three separate areas divided by rock formations, with the caves separated as wide as possible, preferably with entrances facing in different directions so a fish sitting in the doorway won’t be so tempted to go on border patrol.
Plants are not impossible, but their prognosis is guarded. Tough ones like Java fern, which don’t mind too much if they get shoved out of the way, or hardy Anubias growing on stones or pieces of wood are best. Potted plants might work, but if they cannot uproot them, cichlids often shred plants to make sure they will not harbor ambushing predators. You want powerful filtration, either a canister filter or a couple of large hang-on power filters.
For fish, we’ll choose three pairs of Archocentrus or related cichlids. You can pretty much take your pick from any of them, but if you select a milder species like Cryptoheros spilurus, you probably don’t want to also include bruisers like Rocio octofasciata or exCichlasoma salvini.
A good choice for variety, color, size, and compatibility would be three pairs selected from the following for species: convicts (Cryptoheros nigrofasciatus), blue-eyes (C. spilurus), firemouths (Thorichthys meeki), and flyers (Archocentrus centrarchus). All are readily available, about the same size, and of similar habits. To put some activity in the upper part of the tank, and to give the cichlids a target for their aggression, let’s add eight wild swordtails, three males and five females. If you do not want to go for an accurate wild species like Xiphophorus montezumae, then use green swordtails, which are close to the wild form of X. helleri. A school of a dozen Mexican tetras or their cousins, the blind cave tetras, (Astyanax mexicanus), finishes the stocking.
If you can establish a dynamic peace, your cichlids might even spawn. It is doubtful you will raise any young, but with the tenacious parental attentiveness of these fish, it’s possible!
By David Bell
In the June 2012 issue of TFH, I described how I started in the world of nano aquariums. A huge part of my careful planning was identifying what animals I wanted and developing a stocking list.
My must-have fish was a mystery wrasse. I also wished to keep a mix of a few very colorful and smaller fishes such as the secretive fairy or flasher wrasses, demure damsels or percula complex clowns, cardinals, small basslets or grammas, blennies or gobies, and perhaps others to observe their interesting behaviors. I developed the system around those wants. I have basically stuck with my original intention of housing a fish population that averages an adult size of about 3 inches or less. Also, I have always been interested in maintaining a tank exclusively full of hardy and vibrant corallimorpharians, zoanthids and some of the octocorals, as well as a few of the hardier stony corals such as members of the families Faviidae and Mussidae.
Then the challenge came in stocking the aquarium with the right mix of species and number of individuals. I did not plan to have any individuals which would later be moved to a larger tank because they grew too large or acted too aggressively. (However, I do have a seasoned tank already prepared which has come in handy in emergency situations, although it should not be absolutely necessary if the tank is planned correctly.) Ultimately though, I intend to combine this nano reef with one or two other smaller reef systems into a large reef system.
I wound up with this list to begin with.
1 Starry Blenny (Salarias ramosus)
1 Talbot’s Damsel (Chrysiptera talboti)
1 Percula Clownfish (Amphiprion percula)
1 Royal Gramma (Gramma loreto)
1 Tricolor Fairy Wrasse (Cirrhilabrus lubbocki)
1 Mystery Wrasse (Pseudocheilinus ocellatus)
Zoanthids of 14 varieties
Octocorals: Kenya Tree Coral (Capnella imbricata) and Clove Polyps (Clavularia spp.)
Corallimorpharians: Discosoma spp., Rhodactis indosinensis, and Ricordea florida
Duncan Coral (Duncanopsammia axifuga)
Green Plate Coral (Fungia spp.)
Candy Cane Coral (Caulastrea spp.)
Green/Pink Brain Coral (Trachyphyllia spp.)
Green Brain Coral (Acanthastrea spp.)
Red/Dark Red Brain Coral (Acanthastrea spp.)
Pink/Orange Brain Coral (Acanthastrea spp.)
Green/Cream Brain Coral (Favia spp.)
Bright Green Brain Coral (Favites spp.)
Turquoise Brain Coral (Favites spp.)
Red/Blue Micromussa Coral (Micromussa amakusensis)
Multicolored Button Coral (Scolymia spp.)
Red/Orange Button Coral (Lobophyllia spp.)
5 Turbo Snails (Nerita funiculata)
5 Red-legged Hermit Crabs (Clibinarius digueta)
5 Nassarius Snails (Nassarius spp.)
1 Blue Tuxedo Urchin (Mespilia globulus)
Be sure to check out the July 2012 issue of TFH to find out about the progress of these animals, how to overcome challenges presented by nano tanks, and see how it all turned out.
Photograph by David Bell.
By Jennifer Wilkinson
Pearl danios (Danio albolineatus) are pretty little fish that are found in the streams and rivers of Southeast Asia: Burma, Thailand, Sumatra, and the Malayan peninsula. Although most of the ones that we see today are bred in captivity in large fish farms or, occasionally, from hobbyists who spawned the fish.
In the right lighting, these are very beautiful fish; they shimmer and glow with a bluish tinge. I noticed that in some pet shops, they just look like a plain gray fish. When mature, the females are quite a bit larger than the males, however the males are the more colorful of the two. They can reach a size of 2½ inches in length.
I purchased five half-grown fish from a pet store and placed them into a 33-gallon community aquarium. First of all, they should have been placed into a quarantine aquarium before being added to my community, however I was very lucky that these fish were very healthy and did not come down with anything. The aquarium contained several pieces of driftwood and some live plants. It also housed two Ancistrus catfish, twelve Corydoras of two different varieties, and two other kinds of danios. The parameters of this aquarium were a temperature of 78°F, pH 7.2, and the water was fairly soft. Water changes of 30 to 50 percent were done twice a week, or anytime that I over fed.
To condition these fish for spawning, they were fed frozen bloodworms, frozen and live adult brine shrimp, and several different varieties of flakes. These pearl danios were always the first in there to grab the food before any of the others had a chance. One has to make sure that enough food is offered so that everyone gets fed.
These fish do not really school, but they do spend most of their time in the top quarter of the aquarium. They would occasionally be found in other areas of the aquarium, but that was usually when they were chasing food. Unlike other danio species that I have kept, the pearl danio is a very hyper fish; it doesn’t ever seem to slow down.
Pearl danios usually breed over fine-leaved plants, however with my fish, it didn’t seem to matter if plants were available or not. In one of my spawns Java moss was available, however for other spawns it was not. It is quite difficult to tell when these fish are actually breeding because they are so hyper all the time. When they are breeding, they dart around quickly, the male beside the female, and they will slow down—not really stop over the plants or whatever else they are breeding over—and release the eggs. The eggs fall to the bottom and will be eaten if they are not hidden or the parents removed right away.
When breeding action was noticed in the 33-gallon community aquarium, the five fish were moved to a prepared 10-gallon breeding aquarium. This aquarium had a 5-gallon black undergravel filter plate that was held down with aquarium-safe rocks. The rocks had to be placed over the holes where the up lift tubes normally are so these breeding fish could not get underneath and eat all the eggs after the spawning took place. A large clump of Java moss was also placed in beside the filter plate. The water level was down to about half of the aquarium’s volume. The temperature was 78°, pH 7.2, and the water was soft. No filtration was used, only an air stone on very low.
The five adult pearl danios were left in the 10-gallon for two days, then they were moved back to the 33-gallon community aquarium. When the filter plate was removed, the bottom of this aquarium was covered in tiny, clear eggs. These eggs are not sticky, so if some were on the filter plate they would just fall to the bottom. It took three days for all to hatch and another three days for them to become free swimming.
As soon as the fry are free swimming they must be fed. The first food for these very tiny fry was artificial plankton rotifers, and it was fed in small quantities. Some hobbyists just sprinkle it on the top of the water, however I take a very small amount and mix it with water from the aquarium, then pour it in gently so as not to disturb the fry very much. I also do a water change every three days before I add it again. The water changes must be done with a small hand siphon in a very gentle manner so as not to pull out all of the fry. If the fry are accidentally pulled out, they can be put back in with a plastic eye dropper. It is impossible to use a net because these fry are really tiny.
With each water change, a little extra water was added so that the aquarium was full when the fry were big enough to take the flow of a filter. At about three weeks of age they were introduced to baby brine shrimp. At this point most could eat it, and those that couldn’t didn’t survive long. With baby brine shrimp being fed daily, water changes had to be done every night. Baby brine shrimp pollutes the aquarium water very quickly. Shortly after, an outside power filter of the appropriate size to fit the aquarium was added. It was set on the lowest setting, and a sponge was added to the intake tube so none of the tiny fry would get pulled in.
There were so many fry in this spawn that they were moved into a bare 66-gallon aquarium to finish growing out. Most pet stores are happy to take this fish off your hands, however I did run into a few that said they could not sell these fish because they had no color, and therefore they didn’t want them.
Since the first spawn, I have tried some different things when raising these fish. On one occasion I thought it would be interesting to breed and raise two kinds of danios in the same aquarium at the same time, but no, this does not mean cross breeding.
The breeding aquarium was set up the same way as the one mentioned above. Then D. albolineatus were added. They were left for two days, then put back into their community aquarium. I then added two pairs of leopard danios to the breeding aquarium. They were removed the next morning.
When I removed the filter plate the bottom was covered with tiny little eggs—they were literally everywhere. It took all the eggs between one and three days to hatch. This was a good indication that I had eggs from both kinds of danios. It took another four days before all were free swimming. After about a week there was a definite difference: one showed a line along the length of the body and the other fish were a beige color. At this point I wasn’t sure which ones were which. The beige color ones turned out to be the leopard danios, while the ones with the glowing line turned out the be the pearl danios. The leopard danios seemed to grow slightly faster than the pearls. Perhaps that is because the pearl danios are much more hyper, but I’m not sure.
This was quite an enjoyable experiment and quite educational as well.
On another occasion, my cories were breeding up a storm, and there were no aquariums left to raise these eggs, so I moved some of them into the 10-gallon that already contained week-old pearl danio fry. To my surprise, this actually worked! I thought that the cory eggs would fungus because the rotifers were being fed. Instead I ended up with several cory fry. Of course, with so many fry in this 10-gallon aquarium, they had to be moved to larger quarters sooner than normal. It was a good thing that some of the other fish that I was raising were ready to find new homes.
It is not a good thing to over stock the fry aquariums, after all, we are striving for strong, healthy fish. We definitely do not want to see stunted fish. In this case, I knew that the other fish would be finding new homes soon, or I would not have tried raising the cories and so many danios at all.
The pearl danios are a very pretty community fish that do not seem to bother any of other inhabitants. I have housed them in several different communities now and have never had a problem with any of them. The lighting has to be right or they may just look like a dull, gray fish. Remember that they will spend most of their time in the top quarter of the aquarium. The fry that were raised started breeding when they were seven months old. I kept my original five pearl danios for over two years before I gave them away. I did keep some of the fry though.
Tropical Fish Hobbyist’s May 2012 Desktop Calendar is now available!
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Calling all killie fans! St. Louis, Missouri will be the place to be the weekend of May 25-27, where the American Killifish Association will be hosting its 50th Anniversary Convention.
Headlining the event will be a number of speakers and workshops presented by experts including TFH author Mike Hellweg and photographer Tony Teceira.
There will also be an extravagant fish show featuring 17 classes, including South American annuals, Epiplatys, and matched breeding pairs.
Visit the official page for the complete schedule of events and registration information.
Tropical Fish Hobbyist’s April 2012 Desktop Calendar is now available!
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By John Lyons
The stereotype of Mexico is that it is a land of deserts and cactus. Certainly much of the country is arid, but Mexico has a surprising amount of water features that support a diverse number of unique fish fauna. Unfortunately population growth and increasing industrial and agricultural development are degrading these waters at an alarming rate, particularly in the central part of the country. Scientists warn that many of the fishes of central Mexico are in grave jeopardy of extinction.
Fortunately a few areas of central Mexico retain aquatic ecosystems that are largely intact. These areas serve as important reservoirs of biodiversity and reminders of what will likely be lost from the rest of region. One such area is the upper portion of the Río Pánuco basin, located in a rugged, sparsely settled part of the Sierra Madre Oriental mountains, about 200 to 300 kilometers north of Mexico City. The fishes of this part of the Pánuco are little known outside of scientific and specialized aquarist circles, but they have great potential for becoming a part of the broader aquarium hobby.
I had the opportunity to visit the upper Pánuco in February 1999 and assess the status of some of its waters and fishes. I was accompanied by Dr. Henry “Hank” Bart, who is the director and curator of fishes for the Tulane University Museum of Natural History in New Orleans, and Norman Mercado-Silva, who at the time was finishing a thesis on the fishes of the upper Pánuco for his biology degree at the National Autonomous University of Mexico in Mexico City and is now a Research Specialist with the Arizona Cooperative Fish and Wildlife Research Unit, School of Natural Resources.
The journey to the upper Pánuco was full of contrasts. We began in Mexico City, one of the most densely populated valleys on Earth. I’d driven there once before, and that was enough; Norman took the wheel. For an hour he nonchalantly battled the relentless traffic of the city until we finally crested some low hills and gradually emerged into a more agricultural landscape. The air cleaned and the traffic thinned. We passed occasional irrigation ditches and small, nearly dry, earthen ponds, but natural streams were absent. After three hours we reached the pleasant colonial city of Querétaro, where we had lunch and stocked up on beer for the days ahead. Then at last we headed into the Sierra.
Immediately the land became noticeably drier, almost desert-like, and nearly devoid of people. The vegetation was mainly cactus and thorny scrub. The sun was bright and hot. At some point we crossed from the Río Lerma watershed, which drains into the Pacific Ocean, into the Pánuco watershed, which drains into the Gulf of Mexico, but the change was almost imperceptible because the few stream courses we crossed were dry and choked with sand. A handful of small permanent springs occur in this part of the Pánuco basin, but they support only two highly tolerant species, the Mexican tetra (Astyanax mexicanus) and the dusky goodeid (Goodea atripinnis gracilis).
The road began to climb. It wound back and forth up stony canyons and along rocky outcrops. There were magnificent views, but the occasional trucks that barreled toward us from around blind curves discouraged sightseeing. I took over the driving, but Norman and Hank quickly decided that they felt safer in Norman’s experienced hands. As they tactfully put it, they preferred that I “enjoy scenery from the passenger side.”
As we climbed higher the air became cooler and more humid, and the character of the land changed rapidly. Trees replaced cactus and soon we were driving through pine and oak forests interspersed with mountain meadows. Once we crested the western-most range of the Sierra, the landscape became even lusher. This slope intercepted the rain clouds that came off the Gulf of Mexico, leaving little moisture to reach the other side of the mountains. For the first time on the trip we could see natural streams. But this high up the streams were so cold that they could only support only introduced rainbow trout Oncorhynchus mykiss. As night fell we descended toward warmer climes and a good night’s sleep in the valley of the Río Sana María.
The next morning we began our fish surveys. We started on the Río Jalpan, a tributary of the Santa María, about 15 kilometers north of the town of Jalpan along Mexico Highway 69. Since this was the middle of the dry season, the river didn’t have much flow, and you could hop across the riffles on rocks without getting wet. But the pools were still over my head. Big cypress trees lined the banks and made for a picturesque scene, marred only by some piles of garbage along the river bank next to the road.
We could see cichlids in the depths among the cypress roots, but there was no way that we could catch them. However, we seined the edges of the pools and caught other fishes. Most common were the ubiquitous Mexican tetra, the Atlantic molly (Poecilia mexicana), and the porthole livebearer (Poeciliopsis gracilis). The Atlantic mollies were particularly attractive. Females had bright yellowish orange anal fins and orangish speckling on light bluish-gray flanks. Males were more intensely colored, with orange and black anal, dorsal, and tail fins and a darker bluish black body.
Porthole livebearers were distinctively marked with a row of spots along their sides, but had little color. This species is native to southern Mexico and Central America, but has recently become established within central Mexico. In rivers south of Mexico City the introduced porthole livebearer has become abundant and has been blamed for the decline of several native species, so its occurrence in the Pánuco was ominous.
Hank was most excited about our capture of two small, nondescript juvenile fleshy-lip buffalofish (Ictiobus labiosus). Hank is a specialist of the buffalofish, the subfamily Ictiobinae within the sucker family Catostomidae. Buffalofishes are bottom dwellers found mainly in rivers. They often reach large sizes and are important food fish in some areas. Various buffalofishes occur from Canada to Guatemala, but the exact number and identification of species within the group is problematic, particularly in Mexico. The fleshy-lip buffalofish, found only in the upper Pánuco was first recognized and described in 1904, but since then very few individuals have been collected for scientific study and almost nothing has been learned about the species’ biology. The main purpose of Hank’s trip had been to obtain fresh specimens for genetic and morphological analyses. And he was successful at our first site!
After celebrating our find with a hearty breakfast of soda and cookies from a roadside stand, we moved onto the Río Santa María proper at the Highway 69 crossing near the pretty little town of Conca. Here the river was wide and fast flowing, gathering force before it plunged into a rugged and spectacular canyon to the east. As it was a Saturday, families were picnicking and camping on gravel bars along the river. Several were curious about the nets we carried, and offered well-meaning advice (and a few friendly jibes) about how and where to catch fish.
However, despite their suggestions, we caught nothing at first. Where we started the current was too strong and there were no hiding places for the fish. Only when we moved to a boulder-strewn shoreline with slower water did we have success. Initially we encountered a few Mexican tetras and porthole livebearers, and then caught nearly 40 small juvenile fleshylip buffalofish in a single haul of the net. Hank was ecstatic. We ended our sampling with a small Pánuco catfish. This species is found only in the Río Pánuco basin, and grows large enough to be an important food fish for local fishermen. But other than that, scientists know almost nothing of its biology. Unfortunately, this last statement applies to most of the species we encountered during our visit.
After a quick stop in Conca to call home, we headed towards the town of Río Verde, which was to be our base for the next couple of days. I was beginning to feel pretty queasy, a common occupational hazard for me during my years of work in Mexico. Norman was beginning to have doubts about my norteamericano constitution, as the last time I’d been to Mexico he’d had to spend hours calling doctor friends and visiting pharmacies in order to get my insides to a point where I could endure my overnight flight back to the states. But I thought I could manage sampline on more site, the Río Calabazas, a tributary of the Río Verde.
The Río Calabazas at the Highway 69 crossing was wide, shallow, sandy bottomed, slow-moving, and full of aquatic vegetation. Two species of cichlids were common and relatively easy to catch, the black cheek cichlid (Herichthys labridens) and the Río Grande cichlid (H. cyanoguttatus). The Río Grande cichlid is a widespread species native from Texas to the lower part of the Pánuco basin, but it has been introduced into the Río Verde system. Some aquarists consider Río Pánuco populations to be a separate species, H. carpintis. We also captured numerous Pánuco mosquitofish, a small grayish livebearer, and Atlantic mollies. The mollies here were colored differently from those in the Río Jalpan, having less orange in their fins and lighter, more bluish flanks.
We made it to the town of Río Verde before my stomach revolted, but just barely. Fortunately my illness proved to be nothing more than a garden-variety case of turista, and by the next morning I felt much better. Nonetheless we started the day off slowly and didn’t reach our first stop, the Río Tamasopo, until almost noon.
We sampled the river at “Las Cascadas” near the town of Tamasopo. Here the river roke into numerous small channels that flowed over a sharp 15-meter high escarpment, producing a series of lovely waterfalls. At the base of each of the falls was an inviting deep blue pool. In the interests of science we decided to conduct a swimming and diving survey of the largest of these pools. We could see schools of cichlids in the deep water and brilliantly colored Atlantic mollies in the shallows. If we stood still, Mexican tetras would nibble at the hairs on our legs. But the pools were too deep and rocky for our nets, so we moved to one of the outlet channels to collect fish.
Even though the water was slow and shallow and we could see lots of fish, our capture rate was low. The fish were wary and fast, darting under boulders as soon as our nets approached. It took a lot of splashing and stumbling to get a decent sample of the fauna. But the effort was well worth it. In addition to the expected Mexican tetras and Atlantic mollies, we caught Tamasopo cichlids (Herichthys tamasopoensis). This species is closely related to the Río Grande cichlid.
We also collected three Monetzuma swordtails (Xiphophorus montezumae) which was my favorite species of the trip. This type of swordtail is relatively deep-bodied and robust, and the male has a particularly long sword. Both sexes have an attractive spotting pattern and nice yellow-green coloration on their fins and flanks.
It was hard to leave the scenic and relaxing atmosphere of the Tamasopo, but we needed to also sample the Río Gallinas into which the Río Tamasopo flows. Where Highway 70 crossed the Río Gallinas there was no access, so we headed off on a dirt road through a sea of sugar cane fields to find a way down to the river. After blundering about for a while and following some confusing directions from the locals, we found a place where we could get into the water. The river here was wide with lots of boulders and logs, and sampling was challenging. But after a half hour of battling slippery rocks, hidden drop-offs, and shoreline brambles, we were rewarded with a nice pair of Montezuma swordtails, a couple of Tamasopo cichlids, a single Pánuco mosquitofish, and ten pretty Atlantic mollies.
Dusk was approaching, so we hurried off to the nearby town of Ciudad Valles so that Hank and Norman could canvas the fish vendors at the market about the availability of large specimens of buffalofish. I stayed with the truck, studying the map and contemplating dinner options. They soon returned, disappointed because the vendors apparently never saw buffalofish. To cheer them up, I suggested a special dinner of carne asada a la tampiqueña, steak Tampico, one of my favorite dishes. Norman began to ask if I had found out about a good restaurant there in the Ciudad Valles, and then stopped and sighed when he figured out what I had in mind. By now he was getting used to my occasional crazy ideas. “Let’s head right to where it originated,” I said. “Tampico’s only three hours away on the coast.” So off we went, out of the mountains and onto the coastal plain in the gathering darkness. It was a great ride, and really gave us a better perspective on the entire Pánuco basin. But I never got my steak Tampico; the roasted goat on the menu looked too good to pass up.
The next day was our final one in the upper Pánuco basin, and Norman has saved the best location for last, Laguna Media Luna. This deep, crystal-clear lake, located a few kilometers outside the town of Río Verde, was fed by a series of beautiful blue hot springs that kept its temperature a constant 29°C (84°F). The lake is the closest thing to a freshwater coral reef that I’ve ever encountered, with its warm, clear water, thick, coral-like aquatic plant growths, and teeming schools of multicolored fishes.
Near shore were clusters of Atlantic mollies and Tamesi mollies (Poecilia latipunctata). The Atlantic mollies looked similar to those from the Río Jalpan, whereas the Tamesi mollies were less colorful but still very attractive, having a series of dark spots that formed a sort of jagged black lateral stripe on a silver background. Tamesi mollies are native to the lower Pánuco but have been introduced into the Laguna. In midwater were vast aggregations of curious Mexican tetras. Near the bottom a few tessellated pupfish (Cualac tesselatus) could be seen. They are a shy but appealing species with a brilliant spangling of white spots on silver gray flanks. This species in endemic to the lake and surrounding springs and canals; that is, it is found nowhere else on Earth.
However, the stars of the lake’s fish fauna were clearly the cichlids. Four cichlids were presented, two introduced species that were uncommon, the Río Grande cichlid and the Mozambique tilapia (Oreochromis mossambicus), and two native species that were abundant, the black cheek cichlid and the Media Luna cichlid (Herichthys bartoni), which is endemic to the lake and surrounding valley. The blackcheek cichlid came in at least three different color patterns, ranging from nearly all black to a two-tone white back black belly to mostly greenish with black blotches on the sides. The Media Luna cichlid had at least two forms, one with a bright white back and blackish sides and belly and the other with a greenish body, bluish lips and gill covers, and blackish mottling on the sides.
We did not have permission to collect fish within the lake proper, which is a refuge area, so after two hours of blissful snorkeling, we reluctantly moved to one of the outlet irrigation canals from the lake and began sampling. These canals were artificial and lined with concrete. Once we entered one of them, we knew we’d made a mistake. The water was chest deep and the current was very strong. Worse, the bottom was coated with algae and very slippery. It was difficult to stand upright, much less climb up the steep canal walls to get out. When we unrolled our seine to sample, it acted like a sail and we were dragged down the canal by the current. It was a comical scene, at least from Norman’s perspective on the bank.
Sampling wasn’t very productive, although we did take a few Mexican tetras and black cheek cichlids, and one tessellated pupfish. After several splashy failures, we managed to exit the canal with Norman’s help. The last of our beers tasted pretty good at that point.
That was our final fish collection in the upper Pánuco system, and soon thereafter we left the Pánuco basin and went our separate ways. We’d had a great trip, and we’d encountered some fascinating fishes. It was heartening to see that the upper Pánuco still harbored generally healthy stream systems, although we’d seen enough pollution, habitat destruction, and introduced species to make us nervous.
The sites we visited emphasized the tremendous aquatic diversity that still remains in Mexico, and underscored the urgency of improved environmental protection in this rapidly growing nation.
By Charles Clapsaddle
In the “Life with Livebearers” column in the May 2012 issue of TFH, the plight of the dusky goodea (Goodea gracilis) was discussed. The dusky goodea is just one example of a goodeid in trouble, in fact according to Dr. John Lyons and the ALA, most of the goodeids are in danger in their native habitat. Here is the status of each Goodeidae species according to John:
Extinct (no captive populations available): Characodon garmani
Extinct in the Wild (captive populations available): Skiffia francesae
Allodontichthys polylepis (possibly extinct in the wild)
Allotoca goslinei (possibly extinct in the wild)
Hubbsina (Girardinichthys) ireneae
Hubbsina (Girardinichthys) turneri (possibly extinct in the wild)
Neotoca (Skiffia) bilineata
Neophoorus (Allotoca) regalis
Goodea gracilis (= G. atripinnis?)
Ilyodon whitei* (including I. lennoni)
Goodea atripinnis* (including G. luitpoldi)
Ilyodon furcidens* (including I. xantusi)
The asterisks in the table represent species that Dr. Lyons considers to “have large amounts of morphological and/or genetic diversity and have distinctive populations worthy of captive maintenance.” This variation is typical of fish families that have experienced recent rapid speciation.
For the compulsive among my readers, you noticed the ALA only lists 43 instead of 45 species. And the ALA wonders if some of the species are duplicates. Please note that Dr. Lyons indicates that at least some authorities think G. gracilis might be a synonym of G. atripinnis. I’ve kept both fish and am skeptical. They seem distinct to me.
In any event, it’s clear that goodeids are in serious trouble.
photograph by Charles Clapsaddle.
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