Osteology of Tucanoichthys tucano Géry and Römer, an enigmatic miniature fish from the Amazon basin, Brazil (Teleostei: Characiformes: Characidae)

Miniaturization, the evolution of extremely small adult body size, is a common phenomenon across the lineages of freshwater fishes, especially in the Neotropics where over 200 species are considered miniature (≤26 mm in standard length [SL]). Close to 30% of all miniature Neotropical freshwater fishes belong to the family Characidae, several of which are of uncertain phylogenetic placement within the family. We investigate the skeletal anatomy of Tucanoichthys tucano, a species of uncertain phylogenetic position from the upper Rio Negro basin, reaching a maximum known size of 16.6 mm SL. The skeleton of Tucanoichthys is characterized by the complete absence of ten skeletal elements and marked reduction in size and/or complexity of others, especially those elements associated with the cephalic latero-sensory canal system. Missing elements in the skeleton of Tucanoichthys include those that develop relatively late in the ossification sequence of the non-miniature characiform Salminus brasiliensis, suggesting that their absence in Tucanoichthys can be explained by a simple scenario of developmental truncation. A number of the reductions in the skeleton of Tucanoichthys are shared with other miniature characiforms, most notably species of Priocharax and Tyttobrycon, the latter a putative close relative of Tucanoichthys based on molecular data.

RELACIONES ECOLÓGICAS ENTRE ENDOPARASITOS Y EL PEZ SALMINUS BRASILIENSIS (CHARACIDAE) EN UNA LLANURA DE INUNDACIÓN NEOTROPICAL

El presente estudio tuvo como objetivo caracterizar la estructura de la comunidad de parásitos de Salminus brasiliensis en el curso superior del río Paraná a lo largo de las diferentes estaciones del año, entre los niveles de parasitismo y las diferentes características de los huéspedes. La comunidad de parásitos de S. brasiliensis no possuía ninguna especie dominante. Cuatro de las cinco especies de parásitos más prevalentes mostraron distribución agregada. En relación a otros aspectos de la comunidad, cada grupo presentó su parásito en particular, lo que destaca las diferencias inherentes al ciclo de la biología y de la vida de cada especie.

RHINOXENUS BULBOVAGINATUS (MONOGENEA, DACTYLOGYRIDAE) PARÁSITO DE LA CAVIDAD NASAL DE SALMINUS HILARII (CHARACIFORMES, CHARACIDAE) EN UNA RÍO NEOTROPICAL, SP, BRASIL

El objetivo del trabajo es registrar una nueva ocurrencia de Rhinoxenus bulbovaginatus en la cavidad nasal de Salminus hilarii del río Taquari, Estado de São Paulo, Brasil. Rhinoxenus bulbovaginatus fue originalmente descrita parasitando cavidades nasales en Salminus brasiliensis del río Paraná. Rhinoxenus spp. son monogéneos parásitos de las cavidades nasales de los peces Characiformes en la región Neotropical. Hasta la fecha, ocho especies de Rhinoxenus fueron descritas en siete especies hospederas. El presente estudio amplía el rango de hospederos parasitados con monogéneos de las cavidades nasales.

Análise do Consumo da Carne de Peixe em Campo Grande - MS

ResumoEsta pesquisa buscou levantar informações visando oferecer subsídios para o desenvolvimento de estratégias mercadológicas para o aumento do consumo de carne de peixe em Campo Grande - MS. Foi realizada uma pesquisa de campo de caráter exploratório descritiva, por meio da aplicação de um questionário estruturado aplicado a uma amostra aleatória de 404 indivíduos adultos. O questionário buscou identificar o perfil, os hábitos, as atitudes e as preferências, a percepção e o grau de importância, por parte do consumidor, em relação ao consumo de carne de peixe. Constatou-se que a carne de peixe é muito apreciada pelo campo-grandense, principalmente, pelas mulheres (59%). A faixa etária que mais aprecia a carne de peixe está situada entre 31 e 40 anos e renda familiar entre 2 a 4 salários-mínimos. A carne de peixe aparece em terceiro lugar no ranking das preferências. As espécies mais preferidas são pela ordem: pacú (piaractus mesopotamicus), pintado (pseudoplatystoma corruscans), dourado (salminus brasiliensis) e sardinha (Sardinella janeiro). Para aumentar o consumo de carne de peixe são necessárias ações de marketing, que informem aos consumidores sobre a importância nutricional dessa carne, bem como os benefícios que o seu consumo traz para a saúde e aumentar a oferta e a variedade do produto e baixar o seu preço. Palavras-chave: Comportamento do Consumidor. Consumidor de Peixe. Estratégias Mercadológicas. AbstractThis research sought to raise information aiming at offering subsidies for the marketing strategies development for increasing fish meat consumption in Campo Grande city, MS. A descriptive exploratory field survey was conducted through the application of a structured questionnaire applied to a random sample of 404 adult individuals from that city. The questionnaire sought to identify the profile, habits, attitudes and preferences, perception and degree of importance on the part of the consumer in relation to the fish meat consumption. It was observed that fish meat is highly appreciated in Campo Grande city, about 59% are women who showed a higher preference for this type of meat, the age group that most appreciates fish meat is between 31 and 40 years old and family income between 2 and 4 minimum wages. The fish meat appears in third place in the ranking of preferences. The most preferred species are in the order: pacú (piaractus mesopotamicus), pintado (pseudoplatystoma corruscans), dourado (salminus brasiliensis) e sardinha (Sardinella janeiro). To increase the fish meat consumption in Campo Grande, marketing actions are necessary, as well as the benefits that its consumption brings to health. It is also necessary to increase the product supply and variety and lower its price. Keywords: Consumer Behavior. Fish Consumer. Marketing Strategies.

Anthropogenic river fragmentation reduces long-term viability of the migratory fish Salminus brasiliensis (Characiformes: Bryconidae) populations

Life-history, geographical barriers, and damming can shape the genetic diversity of freshwater migratory fish, which are particularly vulnerable to anthropogenic impacts. We investigated the genetic diversity of Salminus brasiliensis, a long-distance migratory species that is recognized as an important provider of ecosystem services. We implemented microsatellite analyses to assess genetic diversity and simulate future scenarios for evaluating the long-term viability of dammed and non-dammed populations from the Uruguay River. High levels of genetic diversity were detected for all sampled populations. However, effective population sizes were lower in the uppermost river stretches, where the landscape is highly fragmented. Population structure analysis indicated two spatial genetic populations. It is suggested that this genetic structure preserves populations partially isolated by an ancient natural barrier, instead of being a result of the presence of dams. The simulated genetic scenarios indicated that genetic variability of S. brasiliensis populations from upstream dams could collapse over the years, mainly due to the reduction in the number of alleles. Therefore, besides helping to better understand issues related to the influence of dams on the genetic diversity of migratory fish, our results are especially relevant for driving local fishery policies and management actions for the species conservation.

Occurrence of non-native species in a subtropical coastal River, in Southern Brazil

Aim This paper aims to concatenate and update the records of non-native species in a subtropical River, in Southern Brazil, warning about their possible impacts in this and other water bodies. Methods Monitoring was carried out in the Guaraguaçu River, the largest River of the Paraná coastal plain, located in the Atlantic Rainforest biome. Fishes were sampled in two periods: from 2002 to 2007 (monthly) and from 2016 to 2018 (semiannually), and the other organisms were collected in isolated samplings. Results The monitoring recorded the presence of six non-native species of animals in this River – four species of fish (Clarias gariepinus, Ictalurus punctatus, Oreochromis niloticus and Salminus brasiliensis), one invertebrate (Macrobrachium rosenbergii) and one foraminifera (Ammoglobigerina globigeriniformis) introduced by escapes from aquaculture, sport fishing and ballast water. These introductions are problematic because they have the potential to impact upon the endangered native species in the River through predation, competition or novel diseases. Conclusions In Guaraguaçu River the increasing number of introductions is worrying because these species have in common a set of traits that turns them into potential invaders. It is of great importance to keep monitoring their populations in order to detect and minimize their negative impacts on native biota, once there is a conservation unit in the region (Guaraguaçu Ecological Station), with the aim to protect the environment in its pristine condition.