scholarly journals The site of loss of water from insects

1934 ◽  
Vol 116 (797) ◽  
pp. 139-149 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Water Balance ◽  
Body Surface ◽  
Water Loss ◽  
Alimentary Canal ◽  
Body Wall ◽  
Body Water ◽  
The Body ◽  
Tracheal System ◽  
Physical Laws

A considerable amount of work has been done with regard to the water-balance of insects (recently summarized by Buxton, 1932), and on the physical laws governing the water loss from insects, but as yet no one has determined exactly from what part of the insect’s body water is lost. It has been found that when insects are not excreting at all, considerable amounts of water are evaporated from their bodies—quantities frequently sufficient to cause death from desiccation. There are three possible ways in which an insect might lose this water (apart from the alimentary canal) : (i) through the general surface of the body wall; (ii) through the spiracular system; and (iii) partly from the body surface and partly through the spiracular system. The fact that carbon dioxide passes readily through chitin (Dewitz, 1890), and that insects get rid of some of that gas through their integument (v. Buddenbrock and Rohr, 1922), suggests that watervapour may also pass from the insect's body in a similar manner. However, Hazelhoff (1927) states that resting insects keep their spiracles closed most of the time, only opening them sufficiently often to obtain enough oxygen, in order to conserve water. He believes that most of the water is lost through the tracheal system. The observations of Gunn (1933) on the cockroach and Mellanby (1932, b ) on the mealworm also suggest that a high proportion of the water evaporated from those insects is lost through the spiracles. The experiments described in this paper show how spiracular opening affects the rate at which insects lose water by evaporation, and the results obtained make it possible to say from what parts of the body this loss takes place.

scholarly journals Microvilli on the External Surfaces of Gastropod Tentacles and Body-Walls

1963 ◽  
Vol s3-104 (68) ◽  
pp. 495-504
Author(s):  
NANCY J. LANE
Keyword(s):  
Free Surface ◽  
Surface Area ◽  
Body Surface ◽  
Body Wall ◽  
Free Cell ◽  
The Body ◽  
Outer Cell ◽  
Lamellar Bodies ◽  
Cell Surfaces ◽  
Histochemical Tests

In Helix aspersa the ‘cuticle’ on the free surface of the external epithelial cells of the optic tentacles has been shown to consist of a layer of microvilli. Microvilli are also present in the same species on the free cell borders of the body-wall, and in the slug Arion hortensis, on the outer cell surfaces of the external epithelium. In all three cases the microvilli are arranged in a hexagonal pattern. There are indications that branching may possibly occur. The microvilli have granular cores with cross- and longitudinal-striations and there are fibrillar connexions between their tips. On the tentacular and body surfaces of H. aspersa, the microvilli increase the surface area 15 and 12 times, respectively. On A. hortensis the increase in surface area is only 4 times. In H. aspersa, beneath the microvilli on the tips of the optic tentacles there is a layer, about 3 to 4 µ deep, composed of vertical, horizontal, and tangential fibres. Some of these fibres are attached to lamellar bodies, which may have a lipid content. Granules are also found among the fibres. Further, a greater depth of cuticle is found to be present on the tips of the inferior tentacles of H. aspersa than on their sides; this seems to indicate that a fibrillar layer, similar to that on the optic tentacles, may lie beneath the cuticle of microvilli on the tips of the inferior tentacles. A thicker cuticle is also found on the tips of the optic tentacles in other stylommatophoran pulmonates. It has not been found possible to ascertain whether the fibrillar layer is intracellular or extracellular, although the evidence points to the latter. Histochemical tests indicate that mucopolysaccharide is present on the surface of the cuticle. Electron micrographs show a granular precipitate caught on and between the fibrillae connecting the tips of the microvilli. It is suggested that the function of the microvilli is to hold the mucous secretions on the body-surface, which would give protection to the animals.

Evolution of water balance in the genusDrosophila

2001 ◽  
Vol 204 (13) ◽  
pp. 2331-2338 ◽  
Author(s):  
Allen G. Gibbs ◽  
Luciano M. Matzkin
Keyword(s):  
Water Balance ◽  
Water Loss ◽  
The Body ◽  
The Other ◽  
Arid Environments ◽  
Physiological Mechanisms ◽  
Dehydration Tolerance ◽  
Cactophilic Drosophila ◽  
Adaptive Mechanisms ◽  
The World

SUMMARYFruit flies of the genus Drosophila have independently invaded deserts around the world on numerous occasions. To understand the physiological mechanisms allowing these small organisms to survive and thrive in arid environments, we performed a phylogenetic analysis of water balance in Drosophila species from different habitats. Desert (cactophilic) species were more resistant to desiccation than mesic ones. This resistance could be accomplished in three ways: by increasing the amount of water in the body, by reducing rates of water loss or by tolerating the loss of a greater percentage of body water (dehydration tolerance). Cactophilic Drosophila lost water less rapidly and appeared to be more tolerant of low water content, although males actually contained less water than their mesic congeners. However, when the phylogenetic relationships between the species were taken into account, greater dehydration tolerance was not correlated with increased desiccation resistance. Therefore, only one of the three expected adaptive mechanisms, lower rates of water loss, has actually evolved in desert Drosophila, and the other apparently adaptive difference between arid and mesic species (increased dehydration tolerance) instead reflects phylogenetic history.

The Evaporation of Water from the Cockroach

1935 ◽  
Vol 12 (4) ◽  
pp. 373-383 ◽  
Author(s):  
J. A. RAMSAY
Keyword(s):  
Wind Velocity ◽  
Body Surface ◽  
Periplaneta Americana ◽  
The Body ◽  
Tracheal System ◽  
Physical Systems ◽  
Change Of State ◽  
Fatty Substance ◽  
Effects Of Temperature ◽  
Rate Of Evaporation

1. The effects of temperature, humidity and wind velocity upon the rate of evaporation of water from the cockroach Periplaneta americana have been studied. 2. The effects of these factors upon the rate of evaporation from the tracheal system are shown to be similar to their effects upon purley physical systems. 3. The effects of these factors upon the rate of evaporation from the body surface are shown to be complicated by the presence of a film of fatty substance which undergoes a change of state at about 30° C.

scholarly journals The Function of the Anal Gills of the Mosquito Larva

1933 ◽  
Vol 10 (1) ◽  
pp. 16-26 ◽  
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Carbon Dioxide ◽  
Body Surface ◽  
Mosquito Larva ◽  
Anterior Part ◽  
Pure Water ◽  
Posterior Part ◽  
The Body ◽  
Glycerol Water ◽  
Hypertonic Solutions ◽  
Spontaneous Aggregation

The anal gills of the mosquito larva (Aedes argenteus) are the only region of the body that is freely permeable to water. In hypertonic solutions of sugar or glycerol, water is extracted from the gills and the larva shrinks. In pure water this is absorbed by the gills and later excreted by the Malpighian tubes. The absorption of water appears to be effected mainly by osmosis. Larvae can mature without the gills, but they seem to grow more slowly, and show almost no parenteral absorption of water. Normally the larva swallows very little fluid. The fluid in the gut is probably secreted in the posterior part of the mid-gut and reabsorbed in the anterior part and in the caeca. Some of the water excreted by the Malpighian tubes is reabsorbed in the rectum. As judged by the spontaneous aggregation of the flagellate Polytoma, oxygen is absorbed by submerged larvae all over the body surface, but most actively at the base of the gills. Carbon dioxide is given off equally all over the body surface. It is concluded that the anal gills are primarily water-absorbing organs, and are only incidentally concerned in respiration.

A comparison of the sites of acid phosphatase activity in an adult filaria, Setaria sp. and in some gastro -intestinal nematodes

Parasitology ◽  
1980 ◽  
Vol 81 (3) ◽  
pp. 603-608 ◽  
Author(s):  
Jun Maki ◽  
Toshio Yanagisawa
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Alimentary Canal ◽  
Body Wall ◽  
The Body ◽  
Luminal Surface ◽  
Toxocara Cati ◽  
Similar Activity ◽  
Very High

SUMMARYThe histochemical localization of acid phosphatase in an adult filaria, Setaria sp. obtained from the peritoneal cavity of a cow was closely examined and compared with that of adult nematodes parasitic in the host alimentary canal; special attention was paid to the intestine and body wall of the parasites. Setaria sp. was found to show high acid phosphatase activity in the interchordal hypodermis of the body wall and uterine microfilariae, and similar activity is suspected to occur in the cuticle. The intestine of this nematode exhibited very low, if any, activity. In contrast, nematodes parasitic on the alimentary canal, such as Toxocara cati, T. canis, Physaloptera sp. and Ancylostoma caninum, showed no activity in the body wall and very high activity in the luminal surface of their intestine. The possible function of the abundant acid phosphatase in the body wall of this filaria is discussed.

On certain Semi-carnivorous Anthomyid Larvae

Parasitology ◽  
1930 ◽  
Vol 22 (2) ◽  
pp. 168-181 ◽  
Author(s):  
D. Keilin ◽  
P. Tate
Keyword(s):  
Alimentary Canal ◽  
Body Wall ◽  
Anatomical Structure ◽  
The Body ◽  
Sensory Organs ◽  
Ventral Region ◽  
Anatomical Features ◽  
Mode Of Life ◽  
Ventral Wall

In previous papers one of us (Keilin, 1915, 1917) has shown that among cyclorrhaphous dipterous larvae there is a remarkable correlation between the anatomical structure of the larvae and their mode of life. Although the mode of life of the larvae is in correlation with such anatomical features as thickness and hardness of the body-wall, the development of sensory organs on the head, and the structure of the alimentary canal, it is in the bucco-pharyngeal armature that the most obvious and important adaptations are to be found. The most important of these adaptations may be mentioned briefly. In certain cyclorrhaphous dipterous larvae the ventral wall of the basal sclerite of the bucco-pharyngeal armature has a number of longitudinal ridges projecting into the lumen of the pharynx. These ridges are usually Y-shaped at their free borders, and form a series of longitudinal channels in the ventral region of the pharynx. In other cyclorrhaphous dipterous larvae such ridges are absent and the ventral wall of the pharynx is smooth. This character allows the larvae to be divided into two groups—“all cyclorrhaphous dipterous larvae parasitic on the most diverse animals or on plants, as well as carnivorous larvae, and larvae which suck the blood of mammals, never have ridges in their pharynx; on the contrary, ridges are always present in saprophagous larvae” (Keilin, 1915). All the larvae which are devoid of ridges and are either parasitic, carnivorous, pass their whole life in the uterus of the female, or are phytophagous, may be united into the group of biontophagous; all larvae which have ridges are saprophagous.

The Penetration of Derris through the Spiracles and Cuticle of Melophagus ovinus, L.

1946 ◽  
Vol 36 (1) ◽  
pp. 15-22 ◽  
Author(s):  
J. E. Webb
Keyword(s):  
Carbon Dioxide ◽  
Temperature Increase ◽  
Muscular Activity ◽  
The Body ◽  
Tracheal System ◽  
Cent Carbon Dioxide ◽  
Melophagus Ovinus

In Melophagus ovinus, derris dust is shown to be absorbed through the spiracles and tracheal system. The amount of dust entering the tracheae is governed by the structure of the inspiratory spiracles and the rate of flow of the inspired air.Factors stimulating the rate of respiration of the insect—i.e., increased muscular activity, the presence of 5 per cent. carbon dioxide and a rise in temperature, increase the rate of entry of derris into the body.Penetration of derris takes place slowly through the external cuticle at 30° C., but not at all at 20°C. It is postulated that the entry of derris through the cuticle probably depends on the hardness of the lipoid layer.

Voluntary dehydration in man

1965 ◽  
Vol 20 (4) ◽  
pp. 719-724 ◽  
Author(s):  
John E. Greenleaf ◽  
Frederick Sargent
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Water Deficit ◽  
Water Intake ◽  
Water Consumption ◽  
Water Loss ◽  
The Body ◽  
Osmotic Concentration ◽  
Voluntary Dehydration ◽  
Ad Libitum

The effects singly and in combination of heat, exercise, and hypohydration upon voluntary dehydration were studied in four acclimated, physically fit, young men. Voluntary dehydration is the delay in complete rehydration following water loss. Hypohydration refers to the state of decreased water content while the osmotic concentration of the body is maintained. Ad libitum drinking during the heat experiments was 146% greater than it was in the cool experiments. Hypohydration increased drinking 109% over the corresponding hydration experiment, exercise increased water intake 41% over resting. Hypohydration and exercise were less effective than heat in stimulating drinking. During the 4-hr experimental periods, the subjects did not or could not drink enough to compensate for the water lost. Regardless of the magnitude of the water deficit at the beginning of the recovery periods, the rates of rehydration were the same. The more stressful the experiment, the greater the water consumption and, in general, the longer it took to regain the lost water. water balance; heat; exercise; drinking; hypohydration Submitted on September 8, 1964

The Post-embryonic Development of Phaenoserphus viator Hal. (Proctotrypoidea), a Parasite of the Larva of Pterostichus niger (Carabidae), with Notes on the Anatomy of the Larva

Parasitology ◽  
1929 ◽  
Vol 21 (1-2) ◽  
pp. 1-21 ◽  
Author(s):  
L. E. S. Eastham
Keyword(s):  
Body Wall ◽  
Larval Instar ◽  
Circulatory System ◽  
The Body ◽  
Suboesophageal Ganglion ◽  
Tracheal System ◽  
Single Host ◽  
History Of ◽  
Cerebral Commissures ◽  
Frontal Ganglion

1. The life-history of Phaenoserphus viator is described.Four larval instars are found, endoparasitic in the larvae of Pterostichus niger. At thee nd of the last larval instar the parasites, which may number as many as 45 in a single host, emerge, and while still attached, pupate without spinning a cocoon.Adults may appear in August or September.The effect of the parasite in inhibiting metamorphosis of the host is discussed.2. The first observed larva is atracheate and incompletely segmented at first and is of the polypod type bearing paired prolegs on the body segments.Subsequent instars are apodate.The tracheal system develops progressively in the several instars, but only becomes functional in the final stage.3. The anatomy of the larva is briefly described with the exception of the musculature.Tracheal development is described. Gas only appears in the tracheae after the development of the tracheole cells puts the tracheae into communication with the body wall and other organs.In the circulatory system an important accessory organ is the neural sinus, formed by the enclosure of the ventral nerve cord beneath a connective tissue curtain.The imaginal discs of the hypodermis are briefly described, these being clearly defined in the head, thorax, and posterior abdominal segments.The nervous system consists of a brain, suboesophageal ganglion and 11 ventral ganglia, the most posterior being tripartite. This system is connected with the sympathetic, by nerves passing from the cerebral commissures to a frontal ganglion which lies above the oesophagus and behind the labrum.

Sign in / Sign up

Export Citation Format

Share Document