Ecología trófica y rasgos ecomorfológicos del pez Triportheus magdalenae (Characiformes: Triportheidae) en el embalse El Guájaro, río Magdalena, Colombia / Trophic ecology and ecomorphological traits of the fish Triportheus magdalenae (Characiformes: Triportheidae) in the El Guájaro reservoir, Magdalena River, Colombia

Resumen Este estudio integró las características ecomorfológicas y la ecología trófica de Triportheus magdalenae en el embalse El Guájaro, Atlántico, bajo Magdalena, Colombia, a partir del análisis del contenido estomacal y rasgos ecomorfológicos. Se realizaron cinco muestreos entre septiembre 2014 y febrero 2016 para abarcar cada momento del pulso de inundación. La recolecta de los peces fue a través de artes de pesca tradicional como atarrayas y redes de arrastre. Se utilizó el índice alimentario (IAi %) para establecer los hábitos alimentarios de la especie, y la variación de la dieta a nivel interespecífico, y se usó el coeficiente de vacuidad (CV %). Se emplearon los índices de Levins Estandarizado por Hurlbert (BA) e índice de Morisita Simplificado para evaluar la amplitud y similitud trófica entre tallas, sexo y momentos hidrológicos. Se caracterizó las estructuras bucofaríngeas y el tracto digestivo, que junto con medidas morfológicas permitieron establecer y analizar 11 rasgos ecomorfológicos relacionados con el uso del hábitat como posición en la columna de agua y la explotación del recurso trófico. Se analizó la relación entre los rasgos ecomorfológicos con la dieta de la especie, por medio de un análisis de correspondencia canónica (ACC). Se analizaron 89 ejemplares (34-190 mm LE). T. magdalenae fue catalogado como carnívoro-zooplanctófago, con un estrecho nicho trófico (BA = 0.12). Se evidenció una alta explotación de los organismos del zooplancton (95.9 IAi %), intensivamente Cladócera (Ceriodaphnia sp.) y Copépoda (Notodiaptomus sp. y Thermocyclops sp), los juveniles (34-190 mm LE) consumieron intensamente los insectos alóctonos (3.4 IAi %). Los rasgos que más aportan a la especialización trófica fueron la longitud relativa de las branquiespinas y el número de branquiespinas, los cuales varían significativamente entre tallas, ya que aumentan en número como en longitud conforme los individuos crecen. El coeficiente de vacuidad fue alto del 54 %, lo cual pudo estar asociado con la disminución en la densidad de las poblaciones de zooplancton, especialmente durante el momento de aguas mínimas fuertemente influenciado por el evento El Niño, sin embargo la dieta observada (22 ítems alimentarios) correspondió al 80 % de la dieta estimada (28 ítems alimentarios estimados).

Abstract This study integrated morphological characteristics and trophic ecology of Triportheus magdalenae in the El Guájaro reservoir, Atlántico, lower Magdalena River Basin, Colombia, based on the analysis of stomach contents and ecomorphological attributes. Five samplings were made between September 2014 and February 2016 considering each phase of the flood pulse. The fish were sampled using traditional fishing gear such as nets and trawls. The index of food importance (IAi %) was used to establish the dietary habits of the species, and the variation of the diet at interspecific level, and the vacuity coefficient (CV %) was also calculated. The Levins index standardized by Hurlbert (BA) was used to evaluate the amplitude between sizes, sex and hydrological phases. The oropharyngeal structures and the digestive tract were characterized, which together with morphological measurements, allowed and analyze 11 ecomorphological traits related to the use of habitat, such as position in the water column, and the exploitation of a particular trophic resource. The relationship between the ecomorphological traits and the diet of the species was analyzed by canonical correspondence analysis (CCA). We analyzed 89 individuals (34-124 mm SL). Triportheus magdalenae was classified as carnivore/zooplanktivore, and has a narrow trophic niche (BA = 0.12). Showed a high exploitation of zooplankton (95.9 % IAi), mostly Cladocera (Ceriodaphnia sp.) and Copepoda (Notodiaptomus sp. and Thermocyclops sp). The youngest juveniles (34-190 mm SL) also consumed allochthonous insects (3.4 % IAi). The ecomorphological traits that contributed the most to this trophic specialization were the relative length of the gillrakers (LRBE). The number of gillrakers (NBE), which varied significantly from the smaller to the larger ones, increase in both number as well as in length as individuals grow, which explains the strongly marked degree of specialization on zooplankton in adults, since they present a greater degree of efficiency in the process of filtering. The vacuity coefficient was high (54 %), which could be associated with a decrease in the density of zooplankton populations, especially during the time of lower waters strongly influenced by the El Niño event, however the observed diet (22 items food) corresponded to 80 % of the diet estimated (28 estimated food items). Rev. Biol. Trop. 66(3): 1208-1222. Epub 2018 September 01.

Resposta hematológica do cascudo ornamental amazônico Peckoltia oligospila ao estresse de transporte / Hematological response of Amazonian ornamental Peckoltia oligospila subjected to stress by transportation

O objetivo deste trabalho foi avaliar as respostas hematológicas do acari-bola Peckoltia oligospila submetido ao estresse de transporte. Variações nos parâmetros de sangue foram analisadas às zero, seis, 24, 48, 72 e 96 horas após o transporte. Respostas ao estresse foram observadas entre zero e seis horas do transporte, mas a maioria dos parâmetros retornou aos valores basais em 24 horas. O tempo de zero hora (momento imediato após transporte) foi o mais crítico, com valores elevados de glicemia, eritrócitos e eritroblastos. Respostas secundárias tardias foram observadas para a proteína plasmática total, o volume corpuscular médio (VCM) e a hemoglobina corpuscular média (HCM) em seis horas após o transporte dos peixes, retornando aos valores basais após esse período. O número de leucócitos não sofreu alterações após o transporte. O estresse de transporte não comprometeu a fisiologia de P. oligospila, o que indica que esse peixe é resistente ao estresse se comparado com outras espécies. Porém, recomenda-se que não se realize qualquer outro procedimento estressante durante pelo menos 24 horas da recuperação dos peixes após transporte, para garantir a saúde e a sobrevivência dos animais transportados.(AU)

The objective of this work was to evaluate the hematological responses of bola-pleco (Peckoltia oligospila) undergoing the stress of transportation. Variations on blood parameters were analyzed at 0, 6, 24, 48, 72 and 96h after transportation. Responses to stress were detected from 0 to 6h after the transportation of fish, however, most parameters returned to baselines values within 24h of transportation. The moment of 0h was the most critical, presenting higher values of glycemia, erythroblasts and erythrocytes. Late secondary responses were observed to total plasmatic protein, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) at 6h, returning to baselines values after this time. Leukocyte number was not affected by stress of transportation. The stress by transportation was not severe to influence the health of P. oligospila, indicating that fish is resistant to stress if compared to other species. However, we recommended no stressful procedures for at least 24 hours for recovery, in order to ensure health and survival of fish.(AU)

Helminth fauna parasitizing Pimelodus pohli (Actinopterygii: Pimelodidae) from the upper São Francisco River, Brazil / Helmintofauna de Pimelodus pohli (Actinopterygii: Pimelodidae) do alto rio São Francisco, Brasil

The parasite fauna of catfish, Pimelodus pohli, from the São Francisco River Basin is presented. A total of 45 catfish from the upper São Francisco River (45°15′44″W 18°13′25″S), were examined from July 2009 to September 2011. Forty-three catfish (95.5%) were infected by at least one parasite species, with 885 parasite specimens being found, distributed across 17 species: Monogenea (Demidospermus uncusvalidus, Pavanelliella pavanellii, and Scleroductus sp.); Eucestoda (plerocercoids of Proteocephalidea); Digenea (metacercariae of Austrodiplostomum compactum, adults of Auriculostoma platense and Kalipharynx sp., and juvenile of Prosthenhystera obesa); Nematoda (larvae of Contracaecum sp., Hysterothylacium sp., Procamallanus pimelodus, Procamallanus sp., and unidentified of Cucullanidae, and adults of Cucullanus caballeroi, Philometra sp., and Procamallanus freitasi); and Acanthocephala (adults of Neoechinorhynchus pimelodi). Procamallanus freitasi and Scleroductus sp. were the taxa with the highest prevalence. Demidospermus uncusvalidus, P. freitasi, and Scleroductus sp. were the dominant species. The host's sex did not influence parasitic indexes; however, the total length of the catfish did appear to have some influence. The parasites, with except for P. obesa, were registered for the first time in P. pohli, as well as the occurrence of Kalipharynx sp. and C. caballeroi among pimelodid hosts from São Francisco River and South America.

A fauna parasitária de mandis, Pimelodus pohli da bacia do rio São Francisco é apresentada. Um total de 45 mandis do alto rio São Francisco (45°15′44″W 18°13′25″S), foram examinados entre julho de 2009 e setembro de 2011. Quarenta e três mandis (95,5%) estavam infectados por pelo menos uma espécie de parasito tendo sido encontrados 885 parasitos de 17 espécies: Monogenea (Demidospermus uncusvalidus, Pavanelliella pavanellii, and Scleroductus sp.); Eucestoda (plerocercóides de Proteocephalidea); Digenea (metacercárias de Austrodiplostomum compactum, adultos de Auriculostoma platense e Kalipharynx sp. e juvenil de Prosthenhystera obesa); Nematoda (larvas de Contracaecum sp., Hysterothylacium sp., Procamallanus pimelodus, Procamallanus sp., larvas não identificadas de Cucullanidae e adultos de Cucullanus caballeroi, Philometra sp. e Procamallanus freitasi); e Acanthocephala (adultos de Neoechinorhynchus pimelodi). Procamallanus freitasi e Scleroductus sp. foram os táxons com prevalência mais elevada. Demidospermus uncusvalidus, P. freitasi e Scleroductus sp. foram as espécies dominantes. O sexo dos hospedeiros não influenciou os índices parasitários, mas houve alguma influência do comprimento total sobre eles. Os parasitos, com exceção de P. obesa, são registrados pela primeira vez em P. pohli, bem como a ocorrência de Kalipharynx sp. e C. caballeroi em hospedeiros pimelodídeos do rio São Francisco e da América do Sul.

Estado de conservación de los peces de la familia Goodeidae (Cyprinodontiformes) en la mesa central de México / Conservation status of Goodeidae familiy fishes (Cyprinodontiformes) from the Mexican Central Plateau

To establish the conservation status and threats for Goodeidae fishes in the high plateau of Mexico, I assessed limnological descriptions,and the reduction in range and in number of localities where they are found, in 53 localities (58.8% of historically reported localities). This assessment included the comparison of current collections with historical records. A principal component analysis of limnological variables showed that most remnant Goodeid species inhabit localities characterised by low environmental degradation: few appear to have a high tolerance to environmental degradation. Overall, 65% of species suffered a reduction in number of localities where they are found. Almost all species face some conservation threat,considering the criteria and categories established by the International Union for the Conservation of Nature (IUCN). Data suggest that one species is extinct (Allotoca catarinae), one more is extinct in the wild (Skiffia francesae), eight are critically endangered (Allodontichthys hubbsi, Allotoca goslinei, Allotoca regalis, Allotoca zacapuensi, Ameca splendens, Characodon audax,Hubbsina turneri,and Zoogoneticus tequila), eleven are endangered, eight can be regarded as vulnerable, four are "near threatened" and only two appear to under "least concern". Habitat loss, introduction of exotic fish, and being species with restricted physiographic range or ecologically specialised, are the main factors leading to the threat of extinction of the Goodeidae family. Recovery actions are needed for the conservation of this fish group.

Se estableció el estado de conservación y se identificaron los riesgos que presentan los peces de la familia Goodeidae en la Mesa Central de México. Para ello se evaluó la disminución en el número de localidades y el área de distribución, y se incorporó una descripción limnológica en 53 localidades. Esta evaluación incluyó una comparación de las colecciones actuales con registros históricos de la distribución de la familia. Un análisis de componentes principales de las variables limnológicas indicó que la mayoría de las especies de goodeidos habitan localidades caracterizadas por tener poca degradación ambiental, y sólo pocas especies parecen tener elevada tolerancia a dicho estado de contaminación. Los resultados de la disminución histórica de localidades y del área de distribución sugieren que el estado de conservación de las especies (de acuerdo con los criterios de la IUCN) es el siguiente: una especie está extinta (Allotoca catarinae), una especie está extinta en la naturaleza (Skiffia francesae, ya que existen ejemplares en cautiverio, ocho están en peligro crítico (Allotoca goslinei, Allotoca regalis, Allotoca zacapuensis, Allodontichthys hubbsi, Ameca splendens, Characodon audax, Hubbsina turneri y Zoogoneticus tequila, once están en peligro, ocho se consideran como vulnerables, cuatro se pueden considerar en riesgo próximo y sólo dos parecen no enfrentar ningún riesgo. En conclusión, la pérdida de hábitat, la introducción de especies exóticas de peces, el ámbito geográfico restringido y la especialización ecológica de las especies son los principales factores de riesgo para las especies estudiadas de la familia Goodeidae. La supervivencia de este grupo requiere acciones para su conservación.