Browsing by Author "Ribeiro, D."
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- Comportamento motor e de brincar numa atividade não estruturada com objetos de cartão numa sala de 1-2 anos de crechePublication . Serrão-Arrais, Ana; Luís, Helena; Rebelo, M.; Crespo, A.; Ribeiro, D.; Rodrigues, M.; Catela, DavidNas atividades não estruturadas, as crianças exploram materiais soltos (i.e., sem funcionalidade evidente, e.g., tubos de cartão) disponibilizados, mas escasseiam estudos com crianças pequenas. Fomos analisar qual o efeito de materiais de cartão sem função evidente, em contexto de creche. Foi dito a 12 crianças (1 a 2 anos; n=8 meninas), da mesma sala, que podiam brincar livremente com vários objetos de cartão do dia-a-dia. Decorrente de análise vídeo, categorias de comportamentos motores obtiveram validação facial e de conteúdo por painel de especialistas. Tipos de brincar [11] também foram analisados. Sem diferenças significativas entre idades ou géneros, quem se envolveu em mais comportamentos motores distintos, esteve mais tempo em atividade motora e com maior frequência de uso de objetos. Ocorreu uma enorme heterogeneidade individual, mas praticamente todas as crianças contactaram todo o tipo de objetos, individualmente ou em pequenos grupos. O tempo médio de atividade motora foi um terço do tempo total da sessão, com elevada diversidade de comportamentos motores. Assim, observou-se uma duração baixa de atividade motora efetiva, mas densa em diversidade e quantidade de habilidades motoras, algumas replicadas em brincar social. Sugerimos verificar o efeito de mais sessões (mesmos materiais, mas em quantidades similares), na duração, densidade e diversidade de comportamentos motores e de brincar social.
- Condition and size of the non-native pikeperch Sander lucioperca (Linnaeus, 1758) in Portuguese river basinsPublication . Gago, João; Neves, A.; Gkenas, C.; Ribeiro, D.; Ribeiro, F.We studied life-history traits focusing on the growth and condition of the pikeperch Sander lucioperca to evaluate its phenotypic plasticity when introduced to new environments. Pikeperch is a non-native fish introduced to Iberian freshwater fauna in 1998 that quickly spread to other river basins through human-mediated activities, occupying now a wide variety of habitats along mainland Portugal. Condition (K and SMI), fork length at age, and length-weight relationships were studied for Portuguese populations. Pikeperch fork length for ages 1, 2, 3, and 4 was different between several populations. We applied generalized linear models (GLM) to study the influence of habitat type, latitude, altitude, time after first detection, and fish prey richness on pikeperch populations size at age 4 and condition. We observed higher condition values on populations from lower altitudes at lentic systems more recently introduced. But higher fork length at age 4 was found in populations from higher altitudes, on older populations with higher prey richness. Habitat type, time since first detection, and fish fauna composition are discussed as the main environmental factors explaining the observed phenotypic plasticity with concerns on predatory impact on native fauna.
- Evaluating the range expansion of recreational non-native fishes in Portuguese freshwaters using scientific and citizen science dataPublication . Martelo, J.; Costa, L. M.; Ribeiro, D.; Gago, João; Magalhães, M. F.; Gante, H. F.; Alves, M. J.; Cheoo, G.; Gkenas, C.; Banha, F.; Gama, M.; Anastácio, P. M.; Tiago, P. M.; Ribeiro, F.Updating information on the distribution of recently introduced and other poorly known non-natives is essential to prevent and control their spread and better address biological invasions. Here, we combine scientific and citizen science data to update the distribution of five recently arrived (i.e., < 25 years), non-native fish species (Alburnus alburnus, Ameiurus melas, Rutilus rutilus, Sander lucioperca and Silurus glanis) and one rare, longer established (i.e., > 50 years), non-native (Esox lucius) in Portugal. These species have been increasingly targeted by recreational fishermen, thus likely expanding their distribution. Specifically, we obtained distribution maps for each species, based on data gathered through a comprehensive search for records in 1) scientific literature, 2) unpublished reports of research projects, and 3) citizen science databases. We gathered 443 valid records, of which 64% were from citizen science data, mainly provided by recreational fishermen. Data highlighted that all species have expanded their distribution in the last 20 years, with high numbers of new records for A. alburnus, S. lucioperca and S. glanis, mostly located in the Tagus, Guadiana and Douro river basins. Changes in species distributions reflected dispersal within invaded basins and colonisation of previously unoccupied drainages. Integrating citizen science with scientific data provides an effective framework to understand non-native species introduction and spread, stressing the need for increasingly encourage and engage recreational fishermen in information sharing.
- Local environment and fragmentation by drought and damming shape different components of native and non-native fish beta diversity across pool refugesPublication . Martelo, J.; Gkenas, C.; Ribeiro, D.; Alves, M.J.; Ribeiro, F.; Cucherousset, J.; Gago, João; Magalhães, M.F.Pool refuges are critical for maintaining stream fish diversity in increasingly intermittent streams. Yet, the patterns and drivers of beta diversity of native and non-native fish in pool refuges remain poorly known. Focusing on Mediterranean streams, we decomposed beta diversity of native and non-native fish into richness difference (RichDiff) and species replacement (Repl), and local (LCBD, LCBDRichDiff and LCBDRepl) and species (SCBD) contributions. We assessed the influence of environmental and spatial factors associated with drought and damming fragmentations on beta diversity components and LCBDs, and of local species richness and occupancy on LCBDs and SCBD, respectively. Overall, non-native species showed a more limited occupancy of pool refuges than native fish. RichDiff dominated beta diversity, though it was influenced by drought and damming fragmentations for native fish and local environment for non-native fish. Repl for native fish was slightly influenced by local environment, but for non-native fish was largely driven by drought and damming, albeit with a contribution of local environment as well. LCBD and LCBDRichDiff increased in pools in low order streams for native fish and at low elevations for non-native fish, and with high or low species richness. SCBD was higher for native species with intermediated pool occupancy, but for non-native species with low occupancy. Our results suggest that stream fragmentation may drive native species loss and non-native species replacement in pool refuges, and that environmental filtering may shape non-native species loss. Pools in lower order streams har bouring unique species-rich or species-poor assemblages should be prioritize for conservation and restoration, respectively, and pools at low elevation with unique non-native assemblages should deserve control efforts. We encourage the partitioning of beta diversity and individual analysis of native and non-native fish in intermittent streams, which may be key in stressing the importance of pool refuges in safeguarding native fish diversity.
- Reproductive traits of the European catfish, Silurus glanis, during the early stages of invasionPublication . Gkenas, C.; Sequeira, V.; Ribeiro, D.; Gago, João; Dias, D.; Verma, C.R.; Kumkar, P.; Ribeiro, F.In recent decades, the European catfish Silurus glanis has spread across Europe and elsewhere, significantly impacting the native fauna of the recipient ecosystems. Studies on its reproductive traits from its non-native range are limited, although this is a critical step in developing effective management plans. Here, we explore the reproductive characteristics of invasive European catfish populations in the Lower River Tagus in Portugal, focusing on its sex ratio, size at maturity, spawning period, fecundity and oocyte diameter. European catfish were collected monthly by electrofishing, gill nets, baited hooks, and professional fishermen from January 2022 to November 2023. A total of 217 females, 156 males and 301 immature fish were analysed. The female-to-male sex ratio was 1.4 : 1, with females and males reaching size at first maturity (TL50) at 72.9 and 68.8 cm total length, respectively. The spawning season was protracted, from February to June, showing asynchronous oocyte development patterns. The absolute fecundity was positively correlated with total length and total weight and ranged from 8,364 to 319,000 oocytes. Relative fecundity varied from 4.39 to 23.53 oocytes, with the mean diameter of the matured oocytes ranging from 1.50 to 3.21 mm. The results obtained in this study enhance our understanding of the reproductive biology of invasive species and can contribute to the development of effective management strategies, such as population control and density- dependent fecundity strategies.
- Variation in diet patterns of the invasive top predator Sander lucioperca (Linnaeus, 1758) across portuguese basinsPublication . Ribeiro, D.; Gkenas, C.; Gago, João; Ribeiro, F.The introduction of non-native species is recognized as a major threat to biodiversity, particularly in freshwater ecosystems. Pikeperch Sander lucioperca, is a recent invader to Portugal, primarily providing commercial and angling interest. The aim of this work was to study the diet of this top predator across Portuguese basins and to evaluate its potential impact on recipient ecosystems. In total, 256 pikeperch stomachs from seven basins were examined, of which 88 (n = 34%) were empty. Pikeperch diet was dominated by R. rutilus, M. salmoides and Diptera in northern populations, while A. alburnus, P. clarkii and Atyidae were important prey in more humid highlands. Variation in diet was most strongly linked to latitude and ontogeny, with both size classes showing signs of cannibalism. The population niche breadth remained low and was accompanied by higher individual diet specialization, particularly in northern populations. Pikeperch dietary patterns denoted an opportunistic ability to use locally abundant prey in each ecosystem, and was size dependent, with larger individuals becoming more piscivores, causing a higher impact in the lotic systems. This first perspective about the pikeperch diet presents a very broad view of the feeding traits of this non-native predator across Portugal, being very important to deepen our knowledge about the impact of these introduced piscivores.
- Westwards expansion of the European catfish Silurus glanis in the Douro River (Portugal)Publication . Gkenas, C.; Martelo, J.; Ribeiro, D.; Gago, João; Santos, G.; Dias, D.; Ribeiro, F.The current study reports the first occurrence and the spread of the European catfish Silurus glanis (Family: Siluridae) in the Portuguese section of the Douro River, suggesting a potential expansion of its distribution in Portugal either via westward dispersal across international rivers and/or human-assisted introductions into new reservoirs and drainages. The European catfish has unique features (e.g., opportunistic predator, hunting, and aggregation behaviour) that make it highly suitable for establishing self-sustaining populations in new areas and likely contribute to its invasion success. The species may severely affect native prey communities and modify food web structure and ecosystem functioning. Efficient and sustainable management actions are needed to prevent further introductions in the future.