An overview of the taxonomic instability of endangered Golden and Zhobi mahseer in Pakistan / Uma visão geral da instabilidade taxonômica do golden em perigo e do Zhobi mahseer no Paquistão

In South and South East Asia three genera of fish species i.e. Tor, Neolissochilus and Naziritor are commonly known as Mahseer with at least 47 species. Among these 23 belongs to genus Tor, 22 to Neolissochilus and one to Naziritor i.e. Naziritor zhobensis. Recently another species added to genus Naziritor is Naziritor chelynoides in India. Among Tor species Tor putitora (Hamilton) is the most widely distributed Mahseer in Pakistan and other countries of the Indian subcontinent. However, based alone on morphological characters some authors identify the Pakistani counterparts as Tor macrolepis (Heckel), (a species presumed to be found exclusively in the Indus River system) distinct from Tor putitora (a species found in Ganga Brahmaputra River system). In order to resolve this taxonomic ambiguity, present study carried out meristic and morphometric measurements of Mahseer collected from a total of 11 water bodies of Pakistan. Ratios between the morphometric characters were calculated and statistically analyzed using t-test and correlation coefficient. Two species identified as Tor putitora and Naziritor zhobensis were the sole Mahseer inhabitants of Indus system in Pakistan. Tor putitora occurred at all surveyed sites while Nazirtor zhobensis had a distribution range from river Zhob to tributaries of river Gomal the right bank tributaries of River Indus. The study corroborates that there are no unequivocal morphological synapomorphies in any existing populations of both species. The study further demonstrates that head length, a character frequently used in Mahseer taxonomy, is not a good measure for species identification. Finally the present study establishes that Naziritor zhobensis still exists in the water bodies of Pakistan and that golden Mahseer occurring in Indus riverine system of Pakistan is Tor putitora.

No sul e sudeste da Ásia, três gêneros de espécies de peixes, ou seja, Tor, Neolissochilus e Naziritor, são comumente conhecidos como Mahseer com pelo menos 47 espécies. Entre estas, 23 pertencem ao gênero Tor, 22 a Neolissochilus e um a Naziritor, ou seja, Naziritor zhobensis. Recentemente, outra espécie adicionada ao gênero Naziritor é Naziritor chelynoides na Índia. Entre as espécies de Tor, Tor putitora (Hamilton) é o Mahseer mais amplamente distribuído no Paquistão e em outros países do subcontinente indiano. No entanto, com base apenas em caracteres morfológicos, alguns autores identificam as contrapartes paquistanesas como Tor macrolepis (Heckel) (uma espécie que se presume ser encontrada exclusivamente no sistema do rio Indo), distinta de Tor putitora (uma espécie encontrada no sistema do rio Ganga Brahmaputra). A fim de resolver essas ambiguidades taxonômicas, o presente estudo realizou medidas merísticas e morfométricas de Mahseer coletadas em um total de 11 corpos d’água do Paquistão. As razões entre os caracteres morfométricos foram calculadas e analisadas estatisticamente usando o teste t e o coeficiente de correlação. Duas espécies identificadas como Tor putitora e Naziritor zhobensis foram os únicos habitantes Mahseer do sistema fluvial Indo no Paquistão. Tor putitora ocorreu em todos os locais pesquisados, enquanto Nazirtor zhobensis tinha uma faixa de distribuição do rio Zhob aos afluentes do rio Gomal, afluentes da margem direita do rio Indo. O estudo corrobora que não há sinapomorfias morfológicas inequívocas em nenhuma das populações existentes de ambas as espécies. O estudo demonstra ainda que o comprimento da cabeça, um caractere frequentemente usado na taxonomia de Mahseer, não é boa medida para identificação das espécies. Finalmente, o presente estudo estabelece que Naziritor zhobensis ainda existe nos corpos d'água do Paquistão e que o Mahseer dourado ocorrendo no sistema fluvial Indo do Paquistão é Tor putitora.

Cambios morfológicos en gametos del barbo tigre Puntius tetrazona (Cypriniformes: Cyprinidae) e implementación de la fertilización in vitro / Morphological changes in gametes of tiger barb Puntius tetrazona (Cypriniformes: Cyprinidae) and the implementation of in vitro fertilization

The production of ornamental fishes represents an economic activity of a growing number of Mexican families. Nevertheless, the reproduction of fish in captivity is one of the complications faced by farmers. This study was set up to: (i) evaluate the morphological and functional changes induced by hydration in the gametes of fish tiger barb (Puntius tetrazona; 240 samples) at tree times after hydration (10, 20 and 30s) with classic spermograms (volume, sperm concentration, viability, motility, and normal morphology); and (ii) evaluate the implementation of in vitro fertilization based on the ovulation rate, the percentage of fertilization and hatching, and the larval numbers obtained after 72 hours. The average volume of milt was 3.0±0.7μL, and the minimum, maximum and average concentration of sperm was 44.4x10(6) spz/mL, 52.3x10(6)spz/mL, and 48.1±5.9x10(6)spz/mL, respectively. The viability and motility of the sperm was 84.6±3.2% and 81.5±2.2%, respectively. The diameter of the sperm with/without water contact was 2.1±0.6μm and 3.8±1.0μm (p<0.05); the largest diameter was recorded 30 seconds after the contact with water. For oocytes, the smaller and larger diameters were recorded at 10 and 30s, respectively (both with/without water contact); the oocytes diameters after 10 and 30 seconds of contact with water were 1.11 and 1.55mm, respectively. A higher ovulation rate was recorded using the in vitro fertilization: 250±50 oocytes versus 28±09 oocytes (during natural fertilization; p<0.05). Nevertheless, fertilization and hatching rates were higher for the natural fertilization (80 and 60%, respectively). Considering the number of larvae obtained after 72 hours, our results showed a higher value for the in vitro fertilization (75±18 compared to 13.4±12 of the natural fertilization; p<0.05). We propose this fish as a model for other ornamental fishes of commercial interest. Our results demonstrate that the in vitro fertilization is a very high viable option to optimize and maximize resources; besides, the reproduction management optimization under controlled conditions may enhance wild fish stocks preservation. Rev. Biol. Trop. 62 (4): 1353-1363. Epub 2014 December 01.

El objetivo del presente estudio fue conocer las características de los gametos de Puntius tetrazona (n=240), los cambios morfológicos a partir de su activación mediante espermogramas cásicos y por otro lado, se evaluó la implementación de la fertilización in vitro a partir de la tasa ovulatoria, el % de fertilización y eclosión y el número de larvas vivas a las 72h. El volumen promedio de semen fue de 3.0±0.7µL. La concentración espermática mínima, máxima y promedio fue 44.48x10(6)spz/mL, 52.3x10(6)spz/mL y 48.1±5.9x10(6)spz/mL, respectivamente. La viabilidad promedio fue de 84.68±3.27%. La motilidad promedio fue 81.53±2.28%. El diámetro de los espermatozoides fluctuó entre 2.16±0.2 y 2.79±0.3µm; 3.84±0.3 y 4.86±0.31µm sin y con contacto con el agua respectivamente, con diferencias significativas. El diámetro mayor fue a los 30s en contacto con el agua. Los ovocitos de menor y mayor diámetro se registraron a los diez y 30s sin y con contacto con el agua respectivamente. Los diámetros de los ovocitos en diez y 30s en contacto con el agua fluctuaron entre 1.11 y 1.55mm respectivamente. La mayor tasa ovulatoria fue en la fertilización in vitro con 250±50 ovocitos frente a 28±09 de la natural, con diferencias significativas. Los porcentajes de fertilización y eclosión fueron más elevados en la fertilización natural con 80% y 60% respectivamente. Se registraron 75±18 larvas a las 72 horas en el grupo in vitro comparado con 13.4±12 larvas de la fertilización natural. Con lo anterior, la técnica que permitió mayor cantidad de larvas fue la de fertilización in vitro.

Detection of morphometric differentiation in Sattar snowtrout, Schizothorax curvifrons (Cypriniformes: Cyprinidae) from Kashmir Himalaya using a truss network system

Schizothorax curvifrons is a morphometrically and meristically most variable and economically valuable promising fish food from Kashmir Valley. Since there is a lack of information on stock structure of wild populations on this species, this study was aimed to investigate the intraspecific variation of this important snowtrout. For this, two rivers and one lake in Kashmir Himalaya were sampled from January 2011 to October 2012. Fish body measurements were taken and morphometric characters using the truss network system was constructed. Altogether, 506 fish specimens were collected. Data were subjected to principal component analysis, discriminant function analysis and univariate analysis of variance. The first principal component explained 63.44% of total variation, while second and third components explained 8.34% and 5.31%, respectively. The step-wise discriminant function analysis retained two variables that significantly discriminated the populations. Using these variables 83.4% of the original specimens were classified into their correct groups and 81.1% of the cross-validated (leave one out procedure) specimens were classified into their correct groups. All of the total 31 transformed truss measurements exhibited highly significant (p<0.001) differences between the populations. This represents the first attempt on stock structure of S. curvifrons; therefore, this study will hopefully guide fisheries taxonomists about its current stock structure and would help in its management and conservation programme across Kashmir Himalaya area.

Schizothorax curvifrons es un alimento para peces, morfométricamente y merísticamente más variable y de mayor valor económico del Valle de Kashmir. Dado que existe una falta de información sobre la estructura de las poblaciones silvestres de esta especie, este estudio tuvo como objetivo investigar la variación intraespecífica de esta importante trucha de nieve. Para ello, se tomaron muestras de dos ríos y un lago en Kashmir Himalaya, de enero 2011 a octubre 2012. Con las mediciones de los peces se construyó una red truss. En total, se recolectaron 506 muestras de peces. Los datos se sometieron a análisis de componentes principales, análisis de función discriminante y el análisis univariante de la varianza. El primer componente principal explicó 63.44% de la variación total, mientras que los componentes segundo y tercero explicaron el 8.34% y 5.31%, respectivamente. El análisis discriminante por etapas, retuvo dos variables que discriminaron significativamente las poblaciones. El uso de estas variables de 83.4% de los especímenes originales se clasificaron en sus grupos correctos y 81.1% de la validación cruzada (deja fuera un procedimiento) especímenes fueron clasificados en sus grupos correctos. Todas las mediciones para entramados transformados, del total de 31, mostraron diferencias altamente significativas (p<0.001) entre las poblaciones. Esto representa el primer intento de obtener la estructura de la población de S. curvifrons, por lo tanto, este estudio espera orientar a los taxonomistas de peces acerca de la estructura de la población actual y ayudar en su manejo y poder establecer un programa de conservación en el área de Kashmir Himalaya.

Biometry of the fishes Barbus plebejus and Barbus capito from Coruh Basin, Turkey

Metric and meristic characters are important to identify fish species and their habitat peculiarities. There are many species that belong to the fish genus Barbus, which is found in tropical and extratropical regions, but there are few studies covering the Coruh basin. Two subspecies of Barbus were found in the Coruh River system of Eastern Anatolia, Turkey: Barbus plebejus escherichi and Barbus capito capito. We collected specimens in seven localities for measurement. The number of vertebra were determined radiographically. Some specimens of B. capito capito have a sharper snout in the segments of Coruh where the water flows faster, suggesting a modification related to current. The biometric measurements vary geographically and could be related to abiotic and biotic factors in the habitat. Rev. Biol. Trop. 57 (1-2): 159-165. Epub 2009 June 30.

Dieta de la carpa Notropis moralesi (Pisces: Cyprinidae) en el río Amacuzac, Morelos, México

Diet of the chub, Notropis moralesi (Pisces: Cyprinidae) in the Amacuzac River, Morelos, Mexico. Notropis moralesi, locally known as "carpa tepelneme", is a small endemic fish of the Papaloapan River. We analyzed its diet and feeding habits. Specimens were captured monthly from Amacuzac, River, Morelos, Mexico. The gut content of 294 specimens was identified to the most specific taxonomic category possible. We quantified gut content by the numerical and frequency of occurrence methods and used the Levin’s amplitude of trophic niche indices and MacArthur and Levin`s indices for niche overlaping. The N. moralesi diet was composed by eleven prey categories, ten of which were of animal item. Chironomids and mayfly were the most consumed prey, independently of season and fish sex or size. We found ten nutritional components in the dry season, and eight in the rainy season. The estimated amplitude of trophic niche (Levin’s method) revealed high values in both seasons. The diet had ten nutritional components in immatures, eight in females and five in males. A Chi-squared test showed not significant differences in the diet by development stage, sex, and season. The niche overlaping index was high (above 0.60) for all analyses. N. moralesi is a carnivorous species with entomophagus tendencies. Rev. Biol. Trop. 57 (1-2): 195-209. Epub 2009 June 30.

Notropis moralesi, conocido comúnmente como "carpa tepelneme", es un pez endémico del río Papaloapan. Se analizó su dieta y hábitos alimentarios. Se tomaron muestras mensuales en el río Amacuzac, Morelos, México. La identificación del contenido estomacal (294 ejemplares) se llevó hasta el taxon más específico posible. Para la cuantificación se utilizaron los métodos numérico (No) y frecuencia de aparición (F.O.). Se utilizó el índice de amplitud de nicho trófico de Levin y el índice de traslape de MacArthur y Levin. N. moralesi presentó la ingestión de once componentes alimenticios, de los cuales diez son de origen animal y uno vegetal. Los quironómidos y efemerópteros fueron los más consumidos independientemente del sexo, talla y época del año. El análisis por épocas del año, reportó diez componentes en el estiaje y ocho en las lluvias. La dieta de los inmaduros estuvo constituida por diez componentes, la de las hembras por ocho y el de los machos por cinco. La prueba de Ji-cuadrada reveló que no existen diferencias significativas entre las dietas por estadio de desarrollo, sexos y épocas del año. El traslape de los nichos tróficos, reveló valores superiores a 0.60 en todas las combinaciones por sexos y épocas del año. N. moralesi es una especie carnívora con tendencias insectívoras y presenta hábitos alimentarios de tipo bentófago.

A survey of metacercariae in cyprinoid fish in Nakhon Ratchasima, northeast Thailand.

Metacercariae were recovered from freshwater fish taken from a stream in Lum Cha Muak, Nakhon Ratchasima Province, northeast Thailand during the year 2000. Seventy-nine cyprinoid fish comprising 3 species (52 Puntius leiacanthus, 22 Cyclocheilichthys armatus, and 5 Hampla dispar) were collected. The prevalence of infection with metacercariae was 51.9%. Only two genera of metacercariae were found: Haplochinae spp and Heterophyidae spp. Haplochinae metacercariae were found in all 3 species of fish, giving rates of infection of 95.5%, 20% and 1.9% for Puntius leiacanthus, Cyclocheilichthys armatus and Hampla dispar respectively. Heterophyidae metacercariae were found only in Puntius leiacanthus, whose infection rate was 30.77%. There were fish intected at the rate of 3.8% with unclassified metacercariae. Interestingly, no fish infected with Opisthorchis viverrini metacercariae were found, which is at odds with previous reports from Thailand in which a higher infection rate was given. This is the first report of fish infected with Haplorchinae spp in Thailand.