María de Lourdes Lozano-Vilano

The fishes of northern and central Veracruz, Mexico

AbstractThe northern and central part of Veracruz, México, as herein delimited, is inhabited by 121 species of fish, in 83 genera and 47 families. Four species and 3 families are Nearctic, 28 species and 6 families are Neotropical, and 1 species is circumtropical. Ecologically, 8 species and 4 families are primary, 25 species and 6 families are secondary, 30 families are peripheral, and 7 families are marine, many of them marine accidentals. A mountainous area near Punta del Morro almost reaches the sea, and acts as a filter for primary and secondary species. Its importance had not been described in detail. From the north, the following species range to Punta del Morro or less:astyanax mexicanus, Dionda ipni, Ictalurus cf.furcatus, I. cf.punctatus, Lucania parva, Cyprinodon variegatus, Gambusia affinis, G. vittata, Heterandria sp.,Poecilia formosa, P. latipinna, Xiphophorus birchmani, X. variatus, Cichlasoma cyanoguttatum, C. labridens andC. sp.. From the south, the species that approach or reach Punta del Morro are:Astyanax aeneus, Hyphessobrycon compressus, Rhamdia guatemalensis, R. laticauda, Rivulus cf.robustus, Belonesox belizanus, Poeciliopsis gracilis, Xiphophorus andersi, X. maculatus, andOphisternon aenigmaticum. Eight species including one peripheral are present on both sides and constitute short penetrations across the barrier. At least nine species represent introductions, purposeful or accidental. Gambusia regani andG. panuco are nominal species of the same form: by first reviser,G. regani is regarded as senior synonym.

Freshwater fish at risk or extinct in México

The Mexican freshwater fish that are at risk orextinct are listed by family, state,basin/region, and causes of risk. Of the 506known species, 168 are at some level of risk,and 25 are believed to be extinct. States withthe most reports are: Chihuahua (46); Coahuila(35); Nuevo León (20); Sonora (19); Durango(18); and Tamaulipas (15). With the exceptionof Sonora, these states are largely located inthe Río Bravo region, and are all arid orsemiarid. Most extinctions have occurred inNuevo León (8) and Coahuila (7). The maincauses of risk reported are: habitat reductionor alteration (86); water depletion (83);presence of exotics (76); small or decliningpopulation (73); and small habitat (57). Allof which result in very local endemism. Thesecauses of risk develop easily when thedistribution is small. The critical factor isaridity, which is associated withdesertization. Water conflicts were to beexpected, and the result is resource nonsustainability.

An annotated distributional checklist of the freshwater fish from Baja California Sur, México

An annotated distributional checklist of thefreshwater fish recorded historically andrecently in Baja California Sur, México, isprovided. This checklist is supported with4,857 specimens collected at freshwaterlocalities during the period of May 1991 toApril 2002, and complemented with a review ofspecimens in museums and in the literature. Thenative ichthyofauna is represented by 19species belonging to 16 genera and 12 families,with only two cases of endemism (Funduluslima and Gobiesox juniperoserrai). Thefirst occurrence of Centropomus viridisin freshwater environments of Baja Californiapeninsula is reported here. The familiesEleotridae and Mugilidae are the most diversewith 3 species each. Zoogeographically, most ofthe species are of tropical affinity(panamanian 63%, tropical amphiamerican 16%and circumtropical 5%) and of marineecological derivation (sporadic 53%,complementary 26%, vicarious 16% anddiadromous 5%). Six species are exotic in thisregion, of which Cyprinus carpio, Xiphophorus helleri and Tilapia cf. zilli are of recent introduction. The currentstatus of the endemic killifish (Funduluslima) is determined as endangered due tocompetition with Tilapia cf. zilliand other exotic fish.An annotated distributional checklist of thefreshwater fish recorded historically andrecently in Baja California Sur, Mexico, isprovided. This checklist is supported with4,857 specimens collected at freshwaterlocalities during the period of May 1991 toApril 2002, and complemented with a review ofspecimens in museums and in the literature. Thenative ichthyofauna is represented by 19species belonging to 16 genera and 12 families,with only two cases of endemism (Funduluslima and Gobiesox juniperoserrai). Thefirst occurrence of Centropomus viridisin freshwater environments of Baja Californiapeninsula is reported here. The familiesEleotridae and Mugilidae are the most diversewith 3 species each. Zoogeographically, most ofthe species are of tropical affinity(panamanian 63%, tropical amphiamerican 16%and circumtropical 5%) and of marineecological derivation (sporadic 53%,complementary 26%, vicarious 16% anddiadromous 5%). Six species are exotic in thisregion, of which Cyprinus carpio, Xiphophorus helleri and Tilapia cf. zilli are of recent introduction. The currentstatus of the endemic killifish (Funduluslima) is determined as endangered due tocompetition with Tilapia cf. zilliand other exotic fish.

Fish biodiversity changes in the Lower Rio Grande/Rio Bravo, 1953–1996

Clearly defined changes in the fishesof the Lower Rio Grande/Rio Bravo, Texas andMexico, have been documented since 1953. Morerecent surveys show that the originalfreshwater fish fauna has been retreating fromthe lower reaches and is being replaced bybrackish and marine invaders. A total of 13localities between Colombia (Nuevo León,México) and the delta (580 km) weresurveyed, with a total fish fauna of 142species, which include native, exotic, andintruding species. Changes were analysed bylocality. These changes show a loss of themajority of freshwater species, replacement oflow to higher salinity forms. This shift isvery clear in marine invaders, with somespecies penetrating the whole areainvestigated. Those changes are morenoticeable in the lower-most localities, anddiminish upstream. Data suggest that thechanges in the basin, reflecting shifts inwhole-basin ecology, include elevatedtemperature, salinity, turbidity, and lowerrunoff levels. There are indications of higherlevels of pollution as well. Informationobtained in this study is being incorporated inan Index of Biological Integrity to appearelsewhere.

ERADICATION OF SPOTTED JEWELFISH, HEMICHROMIS GUTTATUS, FROM POZA SAN JOSÉ DEL ANTEOJO, CUATRO CIÉNEGAS BOLSÓN, COAHUILA, MEXICO

Abstract We report an apparently successful effort to restore native fishes to a pool in the Cuatro Ciénegas Bolsón, Coahuila, Mexico. The results demonstrate the feasibility, in small, confined systems, of eliminating a recently introduced nonnative fish, the spotted jewelfish (Hemichromis guttatus), and transplanting a native fish assemblage from nearby areas. We recommend that similar removal and restoration activities be conducted to protect the unique, highly endemic Cuatro Ciénegas fish fauna.

Phylogeographic analysis of genus Herichthys (Perciformes: Cichlidae), with descriptions of Nosferatu new genus and H. tepehua n. sp.

The genus Herichthys is widely considered to be the monophyletic representative of Cichlidae in northeastern Mexico and southern Texas. It is also the northernmost distributed genus of Neotropical Cichlids. Its distribution stretches over an area that is characterized by an intricate geologic and climatic history that affected its temporal and spatial diversification north of the Trans-Mexican Volcanic-Belt. We access the evolutionary history of the genus Herichthys based on a phylogenetic reconstruction using a mitochondrial fragment of gene Cox1. We evaluate its morphological variation, its correspondence with molecular differentiation and suggest a biogeographical scenario based on a molecular clock and demographic history. Furthermore, we describe Nosferatu new genus, composed of Nosferatu pame (assigned as type species), N. molango, N. pratinus, N. bartoni, N. labridens, N. pantostictus, and N. steindachneri. Genus is characterized by a transition to prolongation in the size of the symphysial pair of teeth relative to that of the other teeth in the outer row of the upper jaw; breeding pigmentation that consists of darkening of ventral area extending over nostrils, opercular series, or pectoral fins; depressed dorsal fin rarely expands beyond anterior third of caudal fin; and an elongated, elastic, smooth caecum adhered to a saccular stomach. We also describe Herichthys tepehua n. sp. found in the Pantepec, Cazones, Tenixtepec, Tecolutla, and Solteros rivers, in Veracruz, Mexico. Moreover, we provide re-descriptions for some of the species in Herichthys and propose a biogeographic hypothesis for both genera, based on available information on the geological and climate history of the area of study, associated to dating retrieved in our phylogenetic analysis.

Morphometric Comparison of Blue Catfish Ictalurus furcatus (Lesueur, 1840) from Northern and Southern Atlantic Drainages of México

Abstract A morphometric comparison was performed on specimens of blue catfish (Ictalurus furcatus) from northern (Lower Río Bravo) and southern (Chiapas) México in order to identify diagnostic characters that allow their discrimination. The discriminant function analysis determined three characters to be highly diagnostic to separate the two groups of specimens: the southern group [SG] has a shorter anal base (mean  =  3.4 times in standard length [SL], range  =  3.1 to 3.7) vs northern group [NG] (mean  =  2.9 times in SL, range  =  2.7 to 3.1), a lesser head width (mean  =  6.0 times in SL, range 5.1 to 6.8) vs NG (mean  =  5.6 times, range  =  5.3 to 6.0), and a lower number of anal rays (mean  =  26, range  =  24 to 28) vs NG (mean  =  31, range  =  29 to 34). Additionally, 14 other characters were also different (P < 0.01) between both groups. All these characters support the taxonomic validation of Ictalurus meridionalis (Günther 1864) for the individuals of SG that are currently included in I. furcatus Lesueur. Studies on comparative osteology and molecular genetics of both forms are needed for the clarification of their taxonomic status.

THE MOUNTAIN CLINGFISH, GOBIESOX FLUVIATILIS (TELEOSTEI: GOBIESOCIDAE), IN THE RÍO CULIACÁN BASIN, SINALOA, MEXICO

Abstract We collected 12 mountain clingfish Gobiesox fluviatilis in the Río Tamazula that represent the first record of the species in both the Río Culiacán basin and the state of Sinaloa, Mexico. We compared proportions of body and counts of fin rays of the new specimens with those previously reported for this species.

Diversity and status of Mexican killifishes.

The name killifish refers to the oviparous secondary freshwater fishes in the order Cyprinodontiformes. Killifishes are abundant in Mexico and are represented by four extant families, Rivulidae, Profundulidae, Fundulidae and Cyprinodontidae, comprising > 50 species in a wide variety of habitats. This paper reviews the current classification of the killifishes of Mexico, as well as aspects of their distribution, biology, ecology and current population conservation status.