Abstract
Branchiostoma senegalense Webb spawns from April to June off the coast of the Spanish Sahara between 23° and 26°N. The larvae drift in a southerly direction, and occur in large numbers off Cap Blanc (20° 55′N; 17° 22′W) from June to December. The gut contents of 3,300 larvae taken from 22 samples were investigated. There was no food in the gut of 18% of these larvae. Phytoplankton (Thalassiosira gravida, Nitzschia seriata, Coscinodiscus eccentricus, Dinophysis acuminata etc.) were found in the gut of the remaining 82%. The guts of three larvae also contained crustaceans (a cyclopoid, a harpacticoid, and an isopod). Since all three crustaceans showed no signs of having been digested, the authors conclude that they actively penetrated into the larvae and were not eaten. Plankton samples were taken from various depths (55 to 25 m and 25 to 0 m) daily (7.30, 12.30, 19.00, 0.15 hrs) at an anchor station, over a period of 10 days. There was no evidence of a diurnal vertical migration of B. senegalense larvae. The larvae were found in various numbers at all depths. No larvae were found on the bottom itself. The larvae of B. senegalense are, thus, genuine plankton organisms.
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Literature Cited
Chin, T. G.: Studies on the biology of the Amoy amphioxus Branchiostoma belcheri (Gray) Philipp. J. Sci. 75, 369–424 (1941).
Gosselck, F. and E. Hagen: Vorkommen und Verbreitung der Larven von Branchiostoma senegalense (Arcania, Branchiostomidae) vor Nord-West-Afrika. Fisch.-Forsch. (In press).
Hartmann, J. und H. Ch. John: Planktische Branchiostoma nordwestlich der Doggerbank (Nordsee). Ber. dt. wiss. Kommn Meeresforsch. 22, 80–84 (1971).
Hausmann, A., L. Postel und W. Woska: Grobquantitative und grobqualitative Untersuchungen am Zooplankton des küstennahen (on shore) und küstenfernen (off shore) Auftriebsgebiet im östlichen Mittelatlantik (F. S. “Alexander von Humboldt” August–November 1970). Diplomarbeit, Universität Rostock, unpublished. 1971.
Van Wijhe, J. W.: On the temporary presence of the primary mouth-opening in the larva of Amphioxus, and the occurrence of three postoral papillae, which are probably homologous with those of the larva of ascidians. Proc. K. ned. Akad. Wet. 29, 286–295 (1926).
—: Observations on the adhesive apparatus and the function of the ilio-colon ring in the living larva of Amphioxus in the growth-period. Proc. K. ned. Akad. Wet. 30, 991–1003 (1927).
Webb, J. E.: On the feeding and behaviour of the larva of Branchiostoma lanceolatum. Mar. Biol. 3, 58–72 (1969).
Wickstead, J. H. and Q. Bone: Ecology of acraniate larvae. Nature, Lond. 184, 1849–1851 (1959).
Wiktor, K.: La composition de la nourriture du maquerau, Scomber colias, des eaux cotiere de l'Afrique du Nord-Quest. ICES Paper No. 1970, J: 7, Copenhagen 1970.
Willey, A.: The later larval development of Amphioxus. Q. Jl microsc. Sci. 32, 183–234 (1891).
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Communicated by O. Kinne, Hamburg
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Gosselck, F., Kuehner, E. Investigations on the biology of Branchiostoma senegalense larvae off the northwest African coast. Marine Biology 22, 67–73 (1973). https://doi.org/10.1007/BF00388911
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DOI: https://doi.org/10.1007/BF00388911