UIE-E - Unidade de Investigação em Eco-Etologia (até 2014)
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- Some features of the territories in the breeding males of the intertidal blenny Lipophrys pholis (Pisces: Blenniidae)Publication . Almada, Vítor Carvalho; Gonçalves, Emanuel João; Oliveira, Rui Filipe; Barata, Eduardo NunoIn this paper we present data on the organization of the territories in males of Lipophrys pholis during the breeding season. Data were collected during high tides by skin- and scubadiving and during low tides by direct inspection of nests. Our study area was located at Arrébida, Portugal. The main results are: (i) The territories of the breeding males of this species are temporary, being established each breeding season, (ii) The guarding males stay in the nest holes with the egg masses while the tide is low and are subjected to several hours of emersion in each tidal cycle, (iii) Even when the nests are submerged the fishes stay inside the nest for an average of 92% of the time. All the activities performed outside the nest correspond to an average of 27 minutes per day. (iv) There was a low frequency of territorial intrusions. Conspecific intruders released a significantly higher frequency of agonistic responses than did Coryphoblennius galerita. (v) Removal experiments showed that vacated territories are not occupied by other males during the same breeding season, (vi) Without the presence of the guarding male the eggs are slowly destroyed by predation and infection, but some eggs can still survive and hatch up to five days after the removal of the parental male. The results are discussed in terms of the probable costs and benefits of breeding intertidally.
- A checklist of the blennioid fishes (Teleostei, Blennioidei) occurring in Portuguese watersPublication . Oliveira, Rui Filipe; Almada, Vítor Carvalho; Almeida, Armando J.; Santos, Ricardo Serrão; Gonçalves, Emanuel JoãoTwenty species of blennioide fishes have been cited from Portuguese waters. A survey of the published literature and personal observations by the authors allowed to confirm the presence of eighteen species: Clinitrachus argentatus, Labrisomus nuchipinnis, Tripterygion delaisi, Blennius ocellaris, Coryphoblennius galerita. Lipophrys canevae, L. dalmatinus, L. pholis, L. trigloides, Parablennius gattorugine, P. pilicornis, P. rouxi, P. ruber, P. incognitus, P. sanguinolentus-parvicornis, Salaria fluviatilis, S. pavo and Ophioblennius atlanticus atlanticus. A check-list is provided with information on the geographic distribution of the confirmed occurences of the blennioid species in portuguese waters.
- A new northern limit for the distribution range of Lipophrys canevae (Pisces: Blenniidae) in the Atlantic OceanPublication . Almada, Vítor Carvalho; Oliveira, Rui Filipe; Gonçalves, Emanuel João; Almeida, Armando J.; Barata, Eduardo NunoIn this note, the occurence of Lipophris canevae at Arrábida (Portugal) is reported, which extends 160 Km north the known range ot this species in the Atlantic coast of the Iberian Peninsula. This species has been consistently found at Arrábida since 1987. The presence of a crest on the head of the males, which is considered a rare secondary sexual character in the Mediterranean populations, is very common in the specimens known from portuguese waters, even in the females, where it is vestigial. The meristic and morphometric data from specimens known from portuguese waters are summarized. At Arrábida, the nests occur in the midlittoral zone, often in the transition to the sublittoral, and remain out of water for several hours during low tide. Breeding takes place during Spring and Summer. ------ SUMÁRIO ----- Na presente nota, descreve-se a ocorrência Lipophris canevae na costa da Arrábida (Portugal), o que estende 160 Km para norte e distribuição conhecida para esta espécie na costa atlântica da Península Ibérica. A ocorrência desta espécie na Arrábida tem sido registada regularmente desde 1987. A presença de uma crista na cabeça dos machos, que para as populações mediterrânicas é considerada um carácter sexual secundário raro, ocorre com grande frequência nos espéciemens conhecudis das águas portuguesas, inclusive nas fêmeas embora nestas seja vestigial. Resumem-se os dados merísticos e morfométricos para os exemplares até agora capturados na costa portuguesa. Na Arrábida, os ninhos ocorrem no médio-litoral, por vezes na transição para o infra-litoral, e permanecem emersos durante várias horas na baixa-mar. A reprodução tem lugar na Primavera e Verão.
- Growth of sprat Sprattus sprattus larvae in the German Bight (North Sea) as inferred by otolith microstructurePublication . Ré, Pedro; Gonçalves, Emanuel JoãoGrowth of sprat larvae was studied in the German Blght of the North Sea and 2 different statlons (stratlfled and mixed water masses) were compared. Sprat larvae were aged using dally growth increments in sagittal otoliths. The daily nature of otolith growth increments was corroborated using the marginal increment technique. The data presented are consistent with the deposition of one complete increment per 24 h period, indicating that at least larvae with lengths greater than 11.0 mm form daily growth increments in their otoliths. There was some evidence that daily growth increments are deposited on the otoliths of sprat larvae only after the onset of exogenous feeding. Integrated somatic growth rate was 0.406 mm d-'. This value is comparable to others obtained for similar pelaglc clupeoid species. There were no significant differences between growth rates at the 2 stations.
- On the occurrence of Parablennius sanguinolentus (Pisces: Blenniidae) on the portuguese coastPublication . Gonçalves, Emanuel João; Almada, Vítor Carvalho; Almeida, Armando J.; Oliveira, Rui FilipeIn this paper we report for the first time the occurrence of Parablennius sanguinolentus in mainland Portuguese waters. Since this species is common in the Mediterranean and in the Bay of Biscay, there appears to be a distributional gap along the Portuguese coast. The present finding, together with recent data on the occurrence of several other blenniids in the Atlantic coast of the Iberian Peninsula, formerly supposed to be Mediterranean endemics, stresses the urgent need for detailed zoogeographical investigations on the inshore fish fauna of south-west Europe.
- The reproductive behavior of the longspine snipefish, Macrorhamphosus scolopax (Syngnathiformes, Macrorhamphosidae)Publication . Oliveira, Rui Filipe; Almada, Vítor Carvalho; Gil, Maria de FátimaAbout two hundred Macrorhamphosus scolopax were observed in a large tank and their behavior was videotaped for subsequent analysis. When not disturbed, the fish moved slowly in a head-down position. Spawning in the tank took place in the last two hours before dark. Courting males change color and actively interact aggressively with other males. They push against each other while swimming in parallel or they charge their opponents with their erected dorsal spine directed at them. Courtship begins near the bottom. After following and swimming parallel to the female the two fish unite tightly by their caudal peduncle, with their ventral regions in close proximity and rise slowly in the water column. During the ascent, the genital papilla of the female extends repeatedly and contacts the genital region of the male.
- Hormonas e comportamento - Aspectos actuais da endocrinologia comportamentalPublication . Oliveira, Rui FilipeNo presente trabalho o autor propõe-se analisar, com base na literatura existente, a relação existente entre hormonas e comportamento. São de salientar os seguintes pontos: (1) Não existe uma hormona específica para determinado comportamento; os comportamentos expressam sim o «resultado final» de um estado fisiológico momentâneo no qual podem estar envolvidas várias hormonas; (2) A relação entre hormonas e comportamento é biunívoca. Não só as hormonas influenciam comportamentos como também estes modulam determinados estados hormonais; (3) AS hormonas podem estar envolvidas no comportamentoa a dois níveis diferentes: durante a ontogenia com um papel organizacional e no animal adulto com um papel activacional. Em ambos os níveis as hormonas podem actuar em quatro sistemas diferente: mecanismos sensoriais, mecanismos motivacionais, mecanismos motores e sobre características somáticas com valor social (e.g., caracteres sexuais secundários). (4) Os estudos de endocrinologia comportamental cometem frequentemente dois tipos de erros: a) Utilizam unidades comportamentais grosseiras, muitas vezes afastadas da realidade biológica da espécie em estudo; b) Na maior parte dos trabalhos em que se recorre à administração de hormonas utilizam-se dosagens farmacológicas e não fisiológicas; (5) Os resultados positivos obtidos com administração de hormonas devem ser encarados cuidadosamente uma vez que a maior parte das hormonas tem um tempo de vida muito curto e os seus metabólitos podem ser biologicamente activos.
- Breeding ecology and nest aggregations in a population of Salaria pavo (Pisces: Blenniidae) in an area where nest sites are very scarcePublication . Almada, Vítor Carvalho; Gonçalves, Emanuel João; Santos, António José; Baptista, Maria CéuIn this paper we present data on the breeding ecology and patterns of nest aggregation in a population ofSalaria pavo (Pisces: Blenniidae), in an area where hard substrates are very scarce. The study site was at Ria Formosa, an extensive littoral lagoon on the south coast of Portugal. The only hard materials available are bricks, tiles, stones and debris that clam culturists use to delimit their fields. The males of S. pavo establish nests intertidally in the holes of the bricks where they guard the eggs. Data were collected at low tide inspections of these artificial ridges and underwater behavioural observations during high tide. The main results are: (i) the same male can establish sequentially more than one nest in the same breeding season; the number of males that stay within the bricks increases before the start of the breeding season and declines towards its end; (ii) there is a large excess of mature males that do not establish nests and they are significantly smaller than the nesting males, suggesting very strong competition for nest sites; (iii) the nests of several males occur in adjacent holes of the same brick, sometimes being entirely surrounded by other nests. Thus, in this population, there is virtually no defended territory around the nest, a situation not known for other blenniid species. This pattern of nest aggregation implies both strong competition among males and reduction of aggression between neighbour parental fishes. This can be explained by the extreme scarcity and spatial distribution of available nest sites.
- Sexual dimorphism and allometry of external morphology in Oreochromis mossambicusPublication . Oliveira, Rui Filipe; Almada, Vítor CarvalhoSexual dimorphism in growth of conventional morphometric characters was investigated in juveniles and young adults (size range: 31 to 91 mm) of Oreochromis mossambicus. A closely associated set of traits was identified that shows sexually dimorphic growth, which was positively allometric in the males. These traits correspond to two different morphological complexes: jaw structure and anal/dorsal fins. The best sex discriminators among this set of traits were premaxilla width, anal fin height and snout length. These findings may be explained in terms of intra- and inter-sexual selection acting together and favouring males with strong and large mouths and high dorsal and anal fins, traits that are important in agonistic displays (jaw and fins), fighting and nest digging (jaw).
- Courting females: Ecological constraints affect sex roles in a natural population of the blenniid fish Salaria pavoPublication . Almada, Vítor Carvalho; Gonçalves, Emanuel João; Oliveira, Rui Filipe; Santos, António JoséInexistente