Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-29T07:44:56.526Z Has data issue: false hasContentIssue false
  • English
  • Français

Chloride regulation and the function of the coxal glands in ticks

Published online by Cambridge University Press:  06 April 2009

A. D. Lees
A. D. Lees
Affiliation:
Agricultural Research Council, Unit of Insect Physiology, London School of Hygiene and Tropical Medicine
Get access Rights & Permissions [Opens in a new window]

Extract

Chloride regulation. Following the ingestion of a blood meal the tick excretes about half the ingested water in the coxal fluid. The mean haemolymph chloride concentration before feeding is 1.00% and after feeding 0.96% NaCl; and that of the coxal fluid, 0.80% NaCl. These results confirm the values given by Boné (1943).

Morphology of the coxal glands. These comprise the coxal glands proper, which elaborate the bulk of the coxal fluid, and the smaller accessory glands of unknown function. Each flask-shaped coxal gland consists of two distinct regions, an outer ‘filtration chamber’ and an inner system of tubules. The latter lead to the external opening. The filtration chamber, which communicates with the tubules at only one point, is highly folded into an elaborate series of pockets and fingers which closely invest the tubules; numerous small muscle fibres inserted in these pockets pass outwards from the gland to attachments on the body wall. The histology of the two regions is entirely different: the filtration membrane is only 1–2μ in thickness and its cellular origin is much obscured: the tubule walls are 5–30 μ in thickness, are composed of cells with a dense, deeply staining cytoplasm, and are richly supplied with tracheae. In Ornithodorus delanoei acinus the walls of the sac-like coxal glands are lined both by ‘filtration membrane’ and by large irregular groups of ‘secretory’ cells; there are no true tubules.

Function of the coxal glands. The production of coxal fluid is under muscular control. It is believed that the contraction of the coxal gland muscles enlarges the filtration chamber and sets up a sufficient pressure difference across the membrane to initiate filtration into the gland. In the subsequent passage of the fluid down the tubules threshold substances such as chloride are reabsorbed. That the coxal fluid is primarily an ultrafiltrate of the haemolymph is suggested by (a) the rapid passage of dyes and even haemoglobin into the coxal fluid after injection into the haemolymph and (b) the very high rate of liberation of fluid. Serum albumen sometimes passes into the coxal fluid after injection but casein (and the normal haemolymph proteins) are fully retained.

Type
Research Article
Information
Parasitology , Volume 37 , Issue 3-4 , August 1946 , pp. 172 - 184
Copyright
Copyright © Cambridge University Press 1946

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Boné, G. J. (1943). Ann. Soc. Zool. Belg. 74, 16.Google Scholar
Christophers, S. R. (1906). Sci. Mem. Med. Sanit. Dep. India, no. 23. Calcutta.Google Scholar
Künssberg, K. (1911). Zool. Anz. 38, 263.Google Scholar
Lees, A. D. (1946). Parasitology, 37, 1.CrossRefGoogle Scholar
Marchoux, E. & Couvy, L. (1913). Ann. Inst. Pasteur, 27, 620.Google Scholar
Nuttall, G. H. F. (1908). J. R. Inst. Publ. Hlth. 16, 385.Google Scholar
Patton, W. S. & Evans, A. M. (1929). Insects, Ticks, Mites and Venomous Animals of Medical and Veterinary Importance. Grubb.Google Scholar
Peters, J. P. & Van Slyke, D. D. (1932). Quantitative Clinical Chemistry. Baillière, Tindall and Cox.Google Scholar
Picken, L. E. R. (1936). J. Exp. Biol. 13, 309.CrossRefGoogle Scholar
Remy, P. (1922). Arch. zool. exp. gén. 61, 1.Google Scholar
Robinson, G. G. (1942). Parasitology, 34, 195.CrossRefGoogle Scholar
Robinson, G. G. (1946). Parasitology, 37, 82.CrossRefGoogle Scholar
Robinson, L. E. & Davidson, J. (1913). Parasitology, 6, 217.CrossRefGoogle Scholar
Roesler, R. (1934). Z. Morph. Ökol. Tiere, 28, 297.CrossRefGoogle Scholar
Ruser, M. (1933). Z. Morph. Ökol. Tiere, 27, 199.CrossRefGoogle Scholar
Samson, K. (1909). Z. wiss. Zool. 93, 185.Google Scholar
Whittick, R. J. (1938). Parasitology, 30, 333.CrossRefGoogle Scholar
Wigglesworth, V. B. (1931). J. Exp. Biol. 8, 411.CrossRefGoogle Scholar
Wigglesworth, V. B. (1937). Biochem. J. 31, 1719.CrossRefGoogle Scholar
Wigglesworth, V. B. (1939). Principles of Insect Physiology. Methuen.Google Scholar