Arthropods Sentence Examples
They secrete a cuticle which never approaches in thickness the often calcified cuticle of Arthropods.
Insect wings are specialized outgrowths of certain thoracic segments, and are quite unrepresented in any other class of Arthropods.
Relationships And Phylogeny The Hexapoda form a very clearly defined class of the Arthropoda, and many recent writers have suggested that they must have arisen independently of other Arthropods from annelid worms, and that the Arthropoda must, therefore, be regarded as an " unnatural," polyphyletic assemblage.
The connexion is not so intimate in Scorpio, but is nevertheless a very close one, closer than we find in any other Arthropods in which the arterial system is well developed, e.g.
On the other hand, in many Arthropods, especially those which possess tracheae, the arteries do not have a long course, but soon open into wide blood sinuses.Advertisement
We are compelled to take a similar view of the agreement between the tracheal air-tubes of Arachnida and other tracheate Arthropods.
Sutures are stated to mark off some of these pieces, but in the proper sense of that term as applied to the skeletal structures of the Vertebrata, no sutures exist in the chitinous cuticle of Arthropods.
Watase, " On the Morphology of the Compound Eyes of Arthropods," Studies from the Biolog.
In the Arcidae the pallial eyes are compound or faceted somewhat like those of Arthropods.
We are driven by the conclusions arrived at as to the derivation of the Arachnida from branchiate ancestors, independently of the other tracheate Arthropods, to formulate the conclusion that tracheae have been independently developed in the Arachnidan class.Advertisement
Watase, " On the Morphology of the Compound Eyes of Arthropods," Studies from the Biol.
Nevertheless, as explained below, it seems to be highly probable that ant-imitating insects and spiders, when the resemblance is dependent to a greater extent upon size, shape and movement than upon tint, have acquired their mimetic likeness especially to protect them from the attacks of such insect-enemies as predaceous wasps of the family Pompilidae, flies of the family Asilidae, and from socalled parasitic hymenoptera of the family Ichneumonidae, as well as from other insect-eating Arthropods.
Aristotle had included in one class "Entoma" the six-legged arthropods which form the modern zoological class of the Hexapoda or Insecta, besides the Arachnida, the centipedes and the millipedes.
This, however, is not the character to which we now ascribe the chief weight as evidence of the genetic affinity and monophyletic (uni-ancestral) origin of the Chaetopods, Rotifers and Arthropods.
A similar constitution of the body is more clearly seen in the Chaetopod worms. In the Vertebrata also a repetition of units of structure (myotomes, vertebrae, &c.) - which is essentially of the same nature as the repetition in Arthropods and Chaetopods, but in many respects subject to peculiar developments - is observed.Advertisement
A satisfactory consideration of the structure of the Arthropods demands a knowledge of what may be called the laws of metamerism, and reference should be made to the article under that head.
From this ancestor Arthropods with heads of varying degrees of complexity have been developed characteristic of the different classes, whilst the parapodia and somites of the body have become variously modified and grouped in these different classes.
The rami may be flattened for swimming, when it is " a bi-ramose swimmeret," or both or only one may be filiform and finely annulate; this is the form often presented by the antennae of Crustacea, and rarely by prae-oral appendages in other Arthropods.
It is difficult in the absence of more detailed knowledge as to the eyes of Chilopoda and Diplopoda to give full value to these facts in tracing the affinities of the various classes of Arthropods.
In regard to tracheae the very natural tendency of zoologists has been until lately to consider them as having once developed and once only, and therefore to hold that a group " Tracheata " should be recognized, including all tracheate Arthropods.Advertisement
All are transmitted by arthropods such as lice, mites and ticks.
Suitable subjects include small arthropods, parts of the same, microfungi, some algae, some botanical preparations.
With the insects they belong to a large group called the arthropods.
Abstract Fossil evidence of terrestrial vascular plant life and terrestrial arthropods exists from the Silurian.
Apart from insects there are some other aquatic arthropods that are worth a closer examination under the microscope.Advertisement
Their flat body enables them to squeeze into extremely narrow cracks and crevices, where they prey on small arthropods and worms.
Well-known examples of complete fossil insects and other related arthropods have been found embedded in pieces of Tertiary amber.
But it is still possible that beneficial arthropods might be indirectly influenced by the presence of the Bt gene.
As the dominant marine arthropods, crustaceans occupy a central and essential position in aquatic food webs.
The cage is certainly readily penetrated by soil (as dust particles) containing virus, bacteria and fungi along with soil arthropods.
The distinguishing feature of all arthropods is the chitinous exoskeleton (Barnes, 1987 ), thus teflubenzuron is lethal to them all.
Our analyzes have focused on insects, birds and mammals, but also other arthropods and a diverse range of simultaneous hermaphrodites.
Foreign genetic material can also be introduced into plant and animal cells by insects and arthropods with sharp mouthparts.
In abundance of species the mollusks constitute the largest invertebrate phylum apart from the Arthropods with over 50,000 described species.
Such a question is not only legitimate, but prompted by the analogy of at least one other great class of Arthropods.
The list of arthropods that bite or sting humans is extensive and includes lice, bedbugs, fleas, mosquitoes, black flies, ants, chiggers, ticks, centipedes, scorpions, and other species.
Arachnid-A large class of arthropods that includes spiders, scorpions, mites, and ticks.
This consideration leads us to one of the most remarkable and fascinating features of 'ant-communities - the presence in the nests of insects and other small arthropods, which are tended and cared for by the ants as their " guests," rendering to the ants in return the sweet food which they desire.
Exoskeleton The outer cellular layer (ectoderm or " hypodermis ") of insects as of other Arthropods, secretes a chitinous cuticle which has to be periodically shed and renewed during the growth of the animal.
The Hexapoda, being aerial, terrestrial and fresh-water animals, are but occasionally preserved in stratified rocks, and our knowledge of extinct members of the class is therefore fragmentary, while the description, as insects, of various obscure fossils, which are perhaps not even Arthropods, has not tended to the advancement of this branch of zoology.
We may conclude, therefore, that they were preceded, in Cambrian times or earlier, by Arthropods possessing well developed appendages on all the trunk-segments.
Of such Arthropods the living Symphyla - of which the delicate little Scutigerella is a fairly well-known example - give us some representation.
The first of these has, in Arachnids as in other Arthropods, its pair of appendages represented by the eyes.
The crural glands, which occur in many terrestrial Arthropods, are epidermal in origin and totally distinct from the coxal glands.
It has been considered by them as proving that Limulus, in spite of all its special agreements with Scorpio (which, however, have scarcely been appreciated by the writers in question), really belongs to the Crustacean line of descent, whilst Scorpio, by possessing Malpighian tubes, is declared to be unmistakably tied together with the other Arachnida to the tracheate Arthropods, the Hexapods, Diplopods, and Chilopods, which all possess Malpighian tubes.
On either side is attached a dorsolateral and ventro-lateral appendage, each with a fan-like plumose termination consisting of compound hairs or setae, found elsewhere only among arthropods (q.v.); each of these is moved by muscles running upwards towards the neck and arising immediately under the trochal disk, the inferior ventro-lateral pair also presenting muscles which form a girdle in the hind region of the body.
It is amongst Arthropods, however - and especially amongst insects - that mimicry, both Batesian and Miillerian, occurs in greatest profusion and perfection.
The structure of the head in Arthropods presents three profoundly separated grades of structure dependent upon the number of prosthomeres which have been assimilated by the prae-oral region.
Arthropods are invertebrates belonging to the phylum Arthropoda, the jointed-leg, spineless creatures of the world.
In connexion with the discussion of the limbs of Arthropods, a few words should be devoted to the gill-processes.
These experiments have shown that Arthropods also have their likes and dislikes in the matter of insect-food and frequently refuse to eat insects which are warningly coloured and are distasteful to vertebrated enemies.