Early growth, yolk and oil globule absorption, early morphological development and initial feeding were studied in the Black Sea turbot Psetta maxima. Based on energy transition and morphological development, the nutritional transition process from endogenous to exogenous sources was divided into six phases: (i) primordial phase (from hatching to ≈ 30 h after hatching, HAH); (ii) organogenesis phase (to ≈ 90 HAH); (iii) onset of feeding (to ≈ 110 HAH); (iv) early feeding (to ≈ 190 HAH); (v) intensified feeding (to ≈ 230 HAH); and (vi) completion of oil globule absorption (to beyond 345 HAH). Based on comparisons with early life stage features of other marine species, the turbot larvae were shown to possess the following characteristics: (i) oil globule remaining for a long period, resulting in an extended mixed feeding period; and (ii) feeding rate extremely high in larvae immediately following final absorption of the oil globule. These features in early turbot larvae were regarded as advantageous for survival in a rearing condition, although the coincidence of initial feeding with completion of yolk absorption signaled a period of leveled‐off growth rate.

Determination of the growth pattern of a harvested species is an important step toward a proper assessment and suitable management of the stock. Although coconut crab Birgus latro populations in most regions have been severely depleted, few reliable biological data are available. We assessed the growth of B. latro using a mark-recapture method based on the use of passive integrated transponder (PIT) tags on Hatoma Island, located southwest of Okinawa, Japan. Of 781 crabs tagged (337 males, 444 females; 14.89 to 58.03 mm thoracic length [ThL]), 17 males and 20 females were recaptured. The application of PIT tags provided field data for growth of individuals for up to 2326 d and confirmed that coconut crabs molt during the winter dry season on Hatoma Island. The curves relating ThL with age, estimated from data of 29 crabs that had spent one or multiple winter dry seasons at liberty, showed that the coconut crab is an extremely slow growing species, with males showing much higher mean asymptotic ThL (69.87 mm) than females (42.79 mm). The Brody growth coefficient (K) was 0.061 yr −1 for males and 0.091 yr −1 for females. This study is the first to provide growth estimates of wild coconut crabs based on markrecapture over multiple years. Potentially long-lived, slow growing species such as coconut crabs may be susceptible to overharvesting, and a cautious approach is recommended to the determination of resource management regimes for B. latro.

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The Mediterranean turbot Psetta maxima consists of two main genetically distinct lineages (western Mediterranean and 'eastern secluded Mediterranean' basins) as investigated by mitochondrial DNA analysis. Within the latter lineage, most haplotypes from the Sea of Azov were endemic and more than half of them derived from a single ancestral haplotype shared among all the eastern Mediterranean areas. There was no relation between morphotype variation in bony tubercles and mitochondrial genealogy. # 2004 The Fisheries Society of the British Isles

Post-release change of home ranges and diel movement patterns of hatchery-reared black-spot tuskfish Choerodon schoenleinii were examined using ultrasonic telemetry. Nine hatchery-reared C. schoenleinii were released in Urasoko Bay, Ishigaki Island, Okinawa, Japan and monitored using ultrasonic telemetry. The fish gradually increased home ranges for c. 3 months before establishing stable home ranges. This pattern of home-range change might have been associated with the learning process of natural environments and intraspecific and interspecific competition. The fish also showed strong diurnal movement patterns: moving horizontally and vertically during the day and staying in the same place at night. The behaviour observed in this study is highly valuable to determine when, where and how to release the fish as well as how to increase the fitness of the fish before releasing.

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To ensure the success of reintroduction programs, it is important to monitor the postrelease behavior and survival of released animals. In this study, the post-release movement and behavior of 5 wild and 5 head-started hawksbill turtles Eretmochelys imbricata were monitored using ultrasonic telemetry. Their dispersal directions and recaptures may indicate that wild turtles perform homing migrations. However, the head-started turtles showed non-uniform patterns in dispersal movements. Four head-started turtles moved out of the monitoring area in various directions, whereas one turtle stayed within the monitoring area for approx. 10 mo. These results might indicate that head-started turtles wander aimlessly in their new surroundings. Signal reception patterns indicated that wild turtles were active in the daytime and rested under the coral at night. Although the head-started turtles also rest at night, their resting places did not seem to be sheltered from hazardous sea conditions or adequate for efficient resting. Therefore, head-started hawksbill turtles appear to need pre-release training such as exposure to structures or ledges in the rearing tank so they can utilize similar structures in the wild for shelter during rest periods and maximize their dive duration by employing these as a roof to counteract the positive buoyant effect of inhaled air. Prey analysis of a head-started turtle captured incidentally demonstrates that these turtles can make feeding adaptations to adjust to the natural environment. These findings provide constructive information for the implementation and improvement of head-start programs.

Post-release movement and diel activity patterns of hatchery-reared and wild blackspot tuskfish were examined using ultrasonic telemetry. Five hatchery-reared and four wild fish were released in the sandy bottom of Urasoko Bay, Ishigaki Island, Okinawa, Japan, and monitored using automated monitoring receivers from November 2005 to February 2006. Both hatchery-reared and wild fish tended to stay near the release site for over two weeks, before leaving the release site. Both hatchery-reared and wild tuskfish showed diurnal rhythm intermittently; signals were recorded more frequently in the daytime and less frequently in the nighttime, suggesting that the fish of both origins were active during the day and inactive during the night. These findings indicate that the one-year-old hatchery-reared tuskfish have some consistent behavioral characteristics with those of the wild.KEY WORDS: acoustic telemetry, behavior, biotelemetry, diel movement, stock enhancement.