Summary
Larvae of the marine mosquito,Aëdes togoi Theobald, tolerate environmental salinities ranging from fresh water to 300% sea water. When they were transferred from fresh water to sea water, sodium concentration in the haemolymph increased for the first 2 days and decreased to the seawater-adapted level within 4 days. When transferred from sea water to fresh water, the sodium concentration decreased markedly for the first 2 days and attained the freshwater adapted level after 4 days. When the larvae in sea water were ligated near the anus, they died within 3 days, showing an increased sodium level in the haemolymph. The larvae ligated at the neck lost considerable body weight and died within 4 days.
When the anal portion, a terminal portion of the hindgut, was catheterized, the larvae maintained in sea water showed an increase in haemolymph sodium. The anal portion epithelium of the larvae adapted to 100 and 150% sea water demonstrated a strong positive reaction to the histochemical assay for chloride ions, whereas the reaction was negative or weakly positive in freshwater adapted larvae. In the larvae with the anal papillae ligated, a slight increase in haemolymph sodium occurred while in sea water. The anal papillae were weakly positive to chloride ions. Unlike salt-water mosquito larvae of the other species, in which the rectum is considered to be involved in hyperosmotic urine production and the anal papillae appear to be the extrarenal organ, the anal portion inA. togoi larvae seems to play an important role in excretion of excess ions when placed in hyperosmotic media.
Similar content being viewed by others
References
Asakura, K.: The anal canal in the sea water larva ofAëdes togoi Theobald. Ann. Rep. Noto Mar. Lab.13, 25–31 (1973) (in Japanese)
Beadle, L.C.: Regulation of the haemolymph in the saline water mosquito larva,Aëdes detritus Edw. J. Exp. Biol.16, 346–362 (1939)
Bradley, T.J., Phillips, J.E.: The secretion of hyperosmotic fluid by the rectum of a saline-water mosquito larva,Aëdes taeniorhynchus. J. Exp. Biol.63, 331–342 (1975)
Bradley, T. J., Phillips, J. E.: Regulation of rectal secretion in saline-water mosquito larvae living in waters of diverse ionic composition. J. Exp. Biol.66, 83–96 (1977a)
Bradley, T.J., Phillips, J.E.: The effect of external salinity on drinking rate and rectal secretion in the larvae of the saline-water mosquito,Aëdes taeniorhynchus. J. Exp. Biol.66, 97–110 (1977b)
Bradley, T.J., Phillips, J.E.: The location and mechanism of hyperosmotic fluid secretion in the rectum of the saline-water mosquito larvae,Aëdes taeniorhynchus. J. Exp. Biol.66, 111–126 (1977c)
Clements, A.N.: The physiology of mosquitoes, pp. 57–71. Oxford: Pergamon Press 1963
Copeland, D.E.: The cytological basis of chloride transfer in the gills ofFundulus heteroclitus J. Morphol.82, 201–227 (1948)
Giese, A.C.: Cell physiology, 2nd ed., pp. 216–221. London, Philadelphia: Saunders 1962
Kiceniuk, J., Phillips, J.E.: Magnesium regulation in mosquito larvae (Aëdes campestris) living in water of high MgSO4 content. J. Exp. Biol.61, 749–760 (1974)
Leader, J.P.: Osmoregulation in the larva of the marine caddis fly,Philanisus plebeius Walk (Trichoptera). J. Exp. Biol.57, 821–838 (1972)
Maddrell, S.H.P., Phillips, J.E.: Active transport of sulphate ions by the Malpighian tubules of larvae of the mosquito,Aëdes campestris. J. Exp. Biol.62, 367–378 (1975)
Matsumoto, A., Matutani, K.: Studies on the mechanisms of ionic regulation in mosquito larvae. I. The measurements of Na and Cl concentrations in haemolymph by radioactivation analysis. Jpn. J. Sanit. Zool.27, 91–95 (1976) (in Japanese)
Matsumoto, A., Matutani, K., Kitada, J., Okada, M.: Studies on the mechanisms of ionic regulation in mosquito larvae. II. The changes and regulation of the concentrations of Na and Cl in the haemolymph of larvae kept in various sea waters. Jpn. J. Sanit. Zool.27, 405–410 (1976) (in Japanese)
Matutani, K., Matsumoto, A.: Studies on the salt regulation in mosquito larvae by radioactivation analysis. Physiol. Ecol. Jpn.17, 167–172 (1976) (in Japanese)
Meredith, J., Phillips, J.E.: Rectal ultrastructure in salt- and fresh-water mosquito larvae in reletion to physiological state. Z. Zellforsch.138, 1–22 (1973a)
Meredith, J., Phillips, J.E.: Ultrastructure of the anal papillae of a salt-water mosquito larva,Aëdes campestris. J. Insect Physiol.19, 1157–1172 (1973b)
Meredith, J., Phillips, J.E.: Ultrastructure of anal papillae from a seawater mosquito larva (Aëdes togoi Theobald). Can. J. Zool.51, 349–353 (1973c)
Nayar, J.K., Sauerman, D.M.: Osmoregulation in larvae of the salt-marsh mosquito,Aëdes taeniorhynchus. Entomol. Exp. Appl.17, 367–380 (1974)
Nicolson, S.W.: Osmoregulation in larvae of the New Zealand salt-water mosquito,Opifex fuscus Hutton. J. Entomol. Ser. A47, 101–108 (1972)
Nicolson, S.W., Leader, J.P.: The permeability to water of the cuticle of the larva ofOpifex fuscus (Hutton). J. Exp. Biol.60, 593–603 (1974)
Phillips, J. E., Bradley, T.J.: Osmotic and ionic regulation in saline-water mosquito larvae. In: Transport of ions and water in animals. Gupta, B.L., Moreton, R.B., Oschman, J.L., Wall, B.J. (eds.), pp. 709–734, London, New York, San Francisco: Academic Press 1977
Phillips, J.E., Meredith, J.: Osmotic and ionic regulation in a salt-water mosquito larva (Aëdes campestris). Am. Zool.9, 588 (1969a)
Phillips, J.E., Meredith, J.: Active sodium and chloride transport by anal papillae of a salt-water mosquito larva (Aëdes campestris). Nature (London)222, 168–169 (1969b)
Ramsay, J.A.: Osmotic regulation in mosquito larvae. J. Exp. Biol.27 145–157 (1950)
Shaw, J., Stobbart, R. H.: Osmotic and ionic regulation in insects. Adv. Insect Physiol.1, 315–399 (1963)
Stobbart, R. H.: Factors affecting the control of body volume in the larvae of the mosquitoes,Aëdes aegypti (L.) andAëdes detritus Edw. J. Exp. Biol.54, 67–82 (1971)
Stobbart, R.H., Shaw, J.: Salt and water balance in excretion. In: The physiology of insecta, Vol. V. Rockstein, M. (ed.), pp. 361–446. New York: Academic Press 1974
Wigglesworth, V.B.: The function of the anal gills of the mosquito larva. J. Exp. Biol.10, 16–26 (1933)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Asakura, K. The anal portion as a salt-excreting organ in a seawater mosquito larva,Aëdes togoi Theobald. J Comp Physiol B 138, 59–65 (1980). https://doi.org/10.1007/BF00688736
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00688736