Embryonic and larval development of the Asian Seabass Lates calcarifer (Pisces: Perciformes: Latidae) under thermostatically controlled conditions

Among the several dozen European freshwater fish species, only European bitterling (Rhodeus amarus Bloch) and Rhodeus meridionalis belong to the group of ostrakophilous fish. The embryonic and larval development of the fish in this reproductive group until the time of the yolk sac resorption takes place in the gill cavity of river mussels (Anodonta sp. or Unio sp.). This paper presents the results of the European bitterling Rhodeus amarus being reared under controlled conditions. Bitterling larvae were caught together with river mussels in the natural environment and subsequently placed in a tank for behavioural observations. Bitterling larvae were seen swimming in the water within a week of placing the bivalves under controlled conditions. The bitterling larvae were 8.6 ± 0.11 mm long when they started to swim actively. The rearing was conducted in water at 20 and 26 ± 0.5 °C and lasted for 6.5 months (200 days) in both variants. Initially, the larvae were fed with live nauplii of Artemia salina and subsequently with fodder. The bitterlings in tanks with water at 26 ± 0.5 °C were 66.2 ± 3.0 mm long and weighed 3389 ± 548 mg. For comparison, bitterlings kept in water at 20 ± 0.5 °C were 64.48 ± 3.4 mm long and weighed 3242 ± 427 mg. No larval malformities or mortality were observed during the larvae and fry rearing. The bitterlings had well-developed secondary sexual characteristics and exhibited pre-spawning behaviour at the end of the rearing. This produced suitable bitterling stocking material to be used in the conservation of small or endangered populations.

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Embryonic and larval development of Gobius paganellus (Pisces: Gobiidae)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315403008415h ◽

2003 ◽

Vol 83 (5) ◽

pp. 1151-1156 ◽

Cited By ~ 11

Author(s):

Rita Borges ◽

Cláudia Faria ◽

Fátima Gil ◽

Emanuel J. Gonçalves ◽

Vitor C. Almada

Keyword(s):

Embryonic Development ◽

Larval Development ◽

Developmental Sequence ◽

Body Form ◽

Total Length ◽

Controlled Conditions ◽

Western European ◽

Newly Hatched Larvae ◽

Embryonic And Larval Development

The full developmental sequence from egg to juvenile of Gobius paganellus under controlled conditions is described. Embryonic development lasted 9–10 days at 18.5–20.0°C and 10–11 days at 15.0–16.5°C. Newly hatched larvae measured 3.90 mm, had the mouth and anus opened, pigmented eyes and almost no yolk. They first settled 25 days after hatching (10.0–10.5 mm total length [TL]) and showed juvenile behaviour and body form 36 days after hatching (14.0 mm TL). However, they only showed full juvenile pigmentation patterns 15 days later (17.0 mm TL) (16.0–16.5°C). In addition, a preliminary differentiation between the newly hatched larvae of the most common Gobius species of south-western European shores is presented.

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