Browsing by Author "Rodrigues, Diana Duarte"
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- Habitat associations and behavioural patterns of Symphodus spp. (Pisces: Labridae)Publication . Rodrigues, Diana Duarte; Costa, Bárbara Horta e; Cabral, Henrique; Gonçalves, Emanuel JoãoThe complexity and diversity of physical and biotic habitats are important features influencing the composition of shallow water reef fish assemblages, especially in temperate regions where abundant and diverse algal cover may have an important habitat-forming role. Coastal fish have adapted to these diverse habitats and to the temporal and spatial variations of algal assemblages in different ways. Wrasses are an important group of coastal rocky reef fish which present particular associations to algae in temperate systems. In this study, habitat associations were analysed in three species of wrasses: Symphodus bailloni, Symphodus melops and Symphodus roissali, and their behaviour was recorded. Eight main behavioural categories (comprising a total of 42 different behaviours) were identified: exploring, foraging, resting, agonistic interactions, cleaning, courtship, reproduction and nesting. S. melops occurred on shallower depths and was frequently involved in both intra- and interspecific agonistic interactions with the other wrasse species, although rarely with S. bailloni. S. roissali was associated with microhabitats of smaller size where it frequently hides. Feeding occurred mostly on bedrock habitat when compared to other microhabitats. Foraging and resting showed a marked seasonality in the three wrasses, related to shifts in biotic habitat structure and to changes in the behavioural repertoire during the breeding season.
- Larval development and allometric growth of the black-faced blenny Tripterygion delaisiPublication . Solomon, Farahnaz N.; Rodrigues, Diana Duarte; Gonçalves, Emanuel João; Serrão, Ester A.; Borges, Rita AlexandraLarval development and allometric growth patterns of the black-faced blenny Tripterygion delaisi are described from a larval series (body length, LB = 3·30-12·10 mm) caught by light traps at the Arrábida Marine Park, Portugal. Larvae of T. delaisi possess distinctive morphometric and meristic characteristics which can be used to identify this species from related taxa. Pigmentation is sparse but characteristic, consisting of pigmented eyes, gas bladder pigmentation in the dorsal region, anal pigmentation and a row of regularly spaced postanal ventral melanophores. This pattern is present from as early as the yolk-sac stage and persists throughout all stages with just the addition of head and caudal pigmentation during the flexion and postflexion stages, respectively. The majority of fin development (with the exception of the caudal fin), occurs in the later stages of development. Myomere counts range between 37 and 45 for all stages. Growth is allometric during larval development. When inflexion points of growth were detected, growth was found to be biphasic with the inflexion points occurring within a very narrow range of LB (8·70-8·90 mm) close to the mean ± s.d. (9·44 ± 1·48 mm LB ) of postflexion larvae. Considering allometric growth patterns and ontogenetic descriptions together, the first developmental phase includes the preflexion and flexion stage larvae, while the second phase characterises the postflexion larvae prior to the transition from larvae to juvenile.
- Larval development and allometric growth of the black-faced blenny Tripterygion delaisiPublication . Solomon, Farahnaz N.; Rodrigues, Diana Duarte; Gonçalves, Emanuel João; Serrão, Ester A.; Borges, Rita AlexandraLarval development and allometric growth patterns of the black-faced blenny Tripterygion delaisi are described from a larval series (body length, LB = 3·30-12·10 mm) caught by light traps at the Arrábida Marine Park, Portugal. Larvae of T. delaisi possess distinctive morphometric and meristic characteristics which can be used to identify this species from related taxa. Pigmentation is sparse but characteristic, consisting of pigmented eyes, gas bladder pigmentation in the dorsal region, anal pigmentation and a row of regularly spaced postanal ventral melanophores. This pattern is present from as early as the yolk-sac stage and persists throughout all stages with just the addition of head and caudal pigmentation during the flexion and postflexion stages, respectively. The majority of fin development (with the exception of the caudal fin), occurs in the later stages of development. Myomere counts range between 37 and 45 for all stages. Growth is allometric during larval development. When inflexion points of growth were detected, growth was found to be biphasic with the inflexion points occurring within a very narrow range of LB (8·70-8·90 mm) close to the mean ± s.d. (9·44 ± 1·48 mm LB ) of postflexion larvae. Considering allometric growth patterns and ontogenetic descriptions together, the first developmental phase includes the preflexion and flexion stage larvae, while the second phase characterises the postflexion larvae prior to the transition from larvae to juvenile.
- Small scale temporal patterns of recruitment and hatching of Atlantic horse mackerel (L.) at a nearshore reef areaPublication . Klein, Maria; Beveren, Elisabeth Van; Rodrigues, Diana Duarte; Serrão, Ester A.; Caselle, Jennifer E.; Gonçalves, Emanuel João; Borges, Rita AlexandraAtlantic horse mackerel (Trachurus trachurus, Linnaeus, 1758) is a highly exploited species, common throughout the North-East Atlantic. As a pelagic-neritic fish it typically occurs over the shelf from the surface to 200 m deep on sandy bottoms. Most research has focused on distributions of adults or early life stages (eggs and larvae) of this species in offshore waters and only a few studies have reported the occurrence of early stages near the coast. However, these nearshore environments might be important for the early growth and survival of the Atlantic horse mackerel. In addition, little is known on how environmental processes might affect the early stages of this species. Here, we monitored weekly recruitment of horse mackerel to artificial substrates (SMURFS) deployed near the coast at both the surface and near the bottom, and back-calculated hatching cohorts. The relationship of both recruitment and hatching patterns with environmental factors was investigated. From a total of 2,515 fish, 2,490 (99%) recruited to surface SMURFS. A GAM and GAMM analysis of the recruitment and hatching patterns, respectively, revealed a strong relationship with the lunar cycle and upwelling. Both recruitment and hatching showed lunar periodicity, with peaks near the new moon and revealed to be influenced negatively by upwelling. This study suggests that the nearshore environment might be an important nursery area for post-larval and early juvenile Atlantic horse mackerel