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Branchiostoma lanceolatum larvae: Some experiments on the effect of thiouracil on metamorphosis

Published online by Cambridge University Press:  11 May 2009

J. H. Wickstead
J. H. Wickstead
Affiliation:
The Plymouth Laboratory
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Extract

Larvae of Branchiostoma lanceolatum (Pallas), of a late pre-metamorphosis stage and characterized by a bright fluorescent green around the ilio-colonic ring, were taken in the Plymouth area plankton in August 1965.

Adults were kept in 0.04% thiouracil to determine the general effect at this concentration. It was lethal over a period of weeks.

The larvae were kept in the dark at a constant temperature of 10° C, individu-ally or in pairs, in 0.04%, 0.02%, 0.01%, 0.005% and 0.0025% thiouracil, in saturated solutions and suspensions of thyroxine and triiodothyronine, and in ordinary sea water. Solutions were changed weekly. The flagellate Dunaliella primolecta Butcher was supplied as food.

All the larvae metamorphosed at approximately the same time and rate, two exceptions being that 0.04% thiouracil was a more obviously toxic concentration and the thyroxine and triiodothyronine larvae were rather more precocious in their metamorphosis.

It is suggested that metamorphosis is a ‘triggered’ process and is self-sustaining. Thus once it has begun it cannot be delayed or accelerated significantly. All the larvae caught were at a stage when this ‘triggering’ had been released.

It is considered possible that the metabolism of the larva and the initiation of metamorphosis is controlled by a secretion of the club-shaped gland.

INTRODUCTION

The position of the amphioxides larva has already been discussed (Wick-stead, 1964). No clear demarcation could be made between the usual type of acraniate larva and amphioxides. It was suggested that the amphioxides was a giant larva, a phenomenon not uncommon in oceanic plankton.

Introduction

The position of the amphioxides larva has already been discussed (Wickstead, 1964).

Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 47 , Issue 1 , February 1967 , pp. 49 - 59
Copyright
Copyright © Marine Biological Association of the United Kingdom 1967

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References

Barrington, E. J. W., 1965. The Biology of Hemichordata and Protochordata. 176 pp. London: Oliver and Boyd.Google Scholar
Bone, Q., 1957. Observations upon the living larva of amphioxus. Pubbl. Staz. zool. Napoli, Vol. 30, pp. 458–71.Google Scholar
Carter, G. S., 1951. A General Zoology of the Invertebrates. 421 pp. London: Sidg-wick and Jackson.Google Scholar
Currie, R. I. & Foxton, P., 1957. A new quantitative net. J. mar. biol. Ass. U.K., Vol. 36, pp. 17–32.CrossRefGoogle Scholar
Goodrich, E. S., 1930. The development of the club-shaped gland in amphioxus. Q. Jl microsc. Sci., Vol. 74, pp. 155–64.Google Scholar
Gordon, A. S., Goldsmith, E. D. & Charipper, H. A., 1943. Effect of thiourea on the development of the amphibian. Nature, Lond., Vol. 152, pp. 504–5.Google Scholar
Jenkins, P. M., 1962. Animal hormones, a comparative survey, Pt. 1. Kinetic and metabolic hormones. 310 pp. London: Pergamon.CrossRefGoogle Scholar
Leuckart, R. & Pagenstecher, A., 1858. Untersuchungen iiber niedere seethiere. Arch. Anat. Physiol., 1858, p. 559.Google Scholar
Muller, J., 1851. U¨ber die Jugendzusta¨nde einiger Seethiere. Mber. Akad. Wiss. Berlin, 1851.Google Scholar
Orton, J. H., 1913–15. On a hermaphrodite specimen of amphioxus with notes on experiments in rearing amphioxus. J. mar. biol. Ass. U.K., Vol. 10, pp. 506–12.CrossRefGoogle Scholar
Sembrat, K., 1953. Effect of the endostyle of the lancelet (Branchiostoma lanceolatum (Pall.)) on the metamorphosis of axolotl. Zoologica Pol., Vol. 6, Fasc. 1, pp. 3–19.Google Scholar
Thomas, I. M., 1956. The accumulation of radioactive iodine by amphioxus. J. mar. biol. Ass. U.K., Vol. 35, pp. 203–10.CrossRefGoogle Scholar
Webb, J. E., 1958. The ecology of Lagos Lagoon. III. The life-history of Branchiostoma nigeriense Webb. Phil. Trans. R. Soc. B, Vol. 241, pp. 393–419.Google Scholar
Wickstead, J. H., 1963. Estimates of total zooplankton in the Zanzibar area of the Indian Ocean with a comparison of the results with two different nets. Proc. zool. Soc. Lond., Vol. 141, pp. 577–608.CrossRefGoogle Scholar
Wickstead, J. H., 1964. The status of the ‘amphioxides’ larva. J. Linn. Soc. (Zool.), Vol. 45, pp. 201–7.CrossRefGoogle Scholar
Wickstead, J. H., 1965. An Introduction to the Study of Tropical Plankton. 160 pp. London: Hutchinson.Google Scholar
Wickstead, J. H. & Bone, Q., 1959. Ecology of acraniate larvae. Nature, Lond., Vol. 184, pp. 1849–51.CrossRefGoogle Scholar
Wijhe, J. W.Van, , 1927, Observations on the adhesive apparatus and the function of ilio-colonring in the living larva of amphioxus in the growth-period. Proc. Sect. Sci. K. ned. Akad. Wet., Vol. 30, pp. 991–1003.Google Scholar
Willey, A., 1894. Amphioxus and the Ancestry of the Vertebrates. 316 pp. London: MacMillan.Google Scholar