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Ocellus
A simple eye or ocellus (sometimes called a pigment pit) is a form of eye or an optical arrangement which has a single lens without the sort of elaborate retina that occurs in most vertebrates. These eyes are called "simple" to distinguish them from " compound eyes", which have multiple lenses. They are not necessarily simple in the sense of being uncomplicated or basic. The structure of an animal's eye is determined by the environment in which it lives, and the behavioural tasks it must fulfill to survive. Arthropods differ widely in the habitats in which they live, as well as their visual requirements for finding food or conspecifics, and avoiding predators. Consequently, an enormous variety of eye types are found in arthropods to overcome visual problems or limitations. Use of the term ''simple eye'' is flexible, and must be interpreted in proper context; for example, the eyes of most large animals are '' camera eyes'' and are sometimes considered "simple" because a sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect
Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, Thorax (insect anatomy), thorax and abdomen (insect anatomy), abdomen), three pairs of jointed Arthropod leg, legs, compound eyes, and a pair of antenna (biology), antennae. Insects are the most diverse group of animals, with more than a million described species; they represent more than half of all animal species. The insect nervous system consists of a insect brain, brain and a ventral nerve cord. Most insects reproduce Oviparous, by laying eggs. Insects Respiratory system of insects, breathe air through a system of Spiracle (arthropods), paired openings along their sides, connected to Trachea#Invertebrates, small tubes that take air directly to the tissues. The blood therefore does not carry oxygen; it is only partly contained in ves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pigment Spot Ocellus
The pigment spot ocellus is an ocellus that contains only part of its cells pigmented. It is characteristic of jellyfish, sea stars, and flatworms Platyhelminthes (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") is a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates commonly called ...."Eye (invertebrate)" McGraw-Hill Encyclopedia of Science & Technology, vol. 6, p.790 2007 References Eye Echinoderm anatomy Cnidarian anatomy Protostome anatomy {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod Eye
Eye#Apposition eyes, Apposition eyes are the most common form of eye, and are presumably the ancestral form of compound eye. They are found in all arthropod groups, although they may have evolved more than once within this phylum. Some annelids and bivalves also have apposition eyes. They are also possessed by ''Limulus'', the horseshoe crab, and there are suggestions that other chelicerates developed their simple eyes by reduction from a compound starting point. Some caterpillars appear to have evolved compound eyes from simple eyes in the opposite fashion. The arthropods ancestrally possessed Eye#Compound eyes, compound eyes, but the type and origin of this eye varies between groups, and some taxa have secondarily developed simple eyes. The organ's development through the lineage can be estimated by comparing groups that branched early, such as the Onychophora, velvet worm and horseshoe crab to the advanced eye condition found in insects and other Synapomorphy, derived arthr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starfish
Starfish or sea stars are Star polygon, star-shaped echinoderms belonging to the class (biology), class Asteroidea (). Common usage frequently finds these names being also applied to brittle star, ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropics, tropical zones to frigid, polar regions of Earth, polar regions. They are found from the intertidal zone down to abyssal zone, abyssal depths, at below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemertea
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of about 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the , a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but wikt:eversion, everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies Filter feeders, filter feed and have suckers at the front and back ends, with which they attach to a Hos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nocturnality
Nocturnality is a behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Some animals, such as ferrets, have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal). Others, such as bushbabies and (some) bats, can function only at night. Many nocturnal creatures including tarsiers and some owls have large eyes in comparison with their body size to compensate for the lower light levels at night. More specifically, they have been found to have a larger cornea relative to their eye size than diurnal creatures to increase their : in the low-light conditions. Nocturnality helps wasps, such as ''Apoica flavissima'', avoid hunting in intense sunlight. Diurnal animals, including humans (except for ni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clynotis Severus, AF 2
''Clynotis'' is a genus of spiders in the family Salticidae, or jumping spiders, contained within the subfamily Marpissinae. They are found across Australia and New Zealand, with some species occupying the Auckland Islands and one found exclusively on Snares Island. There are eight species currently described within the genus, the earliest noted being the type species ''Clynotis severus'', first described in Queensland, New South Wales, Australia in 1879 by Ludwig Carl Christian Koch. The most recent was described in 1931 by Lucien Berland. Two other species previously held within the genus were subsequently reclassified into the genus '' Tara''. As with most salticidae spiders, members of this genus are known for their ability to jump with agility, and for their strong vision. They are identifiable from the distinct shape of the cephalothorax and their eye patterns. Of their eight eyes, the front row of four feature a dramatically prominent anterior median pair, while the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mantle (mollusc)
The mantle (also known by the Latin language, Latin word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the dorsum (biology), dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself. In many species of molluscs the Epidermis (skin), epidermis of the mantle secretes calcium carbonate and conchiolin, and creates a mollusc shell, shell. In sea slugs there is a progressive loss of the shell and the mantle becomes the dorsal surface of the animal. The words mantle and pallium both originally meant ‘cloak’ or ‘cape’; see mantle (vesture). This anatomical structure in molluscs often resembles a cloak because in many groups the edges of the mantle, usually referred to as the ''mantle margin'', extend far beyond the main part of the body, forming flaps, double-layered structures which have been adapted for many different uses, including for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Clam
''Tridacna gigas'', the giant clam, is the best-known species of the giant clam genus ''Tridacna''. Giant clams are the largest living bivalve molluscs. Several other species of "giant clam" in the genus ''Tridacna'' are often misidentified as ''Tridacna gigas''. These clams were known to indigenous peoples of East Asia for thousands of years and the Venetian scholar and explorer Antonio Pigafetta documented them in a journal as early as 1521. One of a number of large clam species native to the shallow coral reefs of the South Pacific and Indian oceans, they may weigh more than , measure as much as across, and have an average lifespan in the wild of more than 100 years. They also are found off the shores of the Philippines and in the South China Sea in the coral reefs of Malaysia. The giant clam lives in flat coral sand or broken coral and may be found at depths of as great as 20 m (66 ft). Its range covers the Indo-Pacific, but populations are diminishing quickly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strombidae
Strombidae, common name, commonly known as the true conchs, is a Taxonomy (biology), taxonomic family (biology), family of medium-sized to very large sea snails in the superfamily (zoology), superfamily Stromboidea, and the Epifamily Neostromboidae. The term true conchs, being a common name, does not have an exact meaning. It may generally refer to any of the Strombidae but sometimes is used more specifically to include only ''Strombus'' and ''Lambis''.Goodenough, W. H. & Sugita, H. (1980).Trukese-English dictionary. Philadelphia: American Philosophical Society. p. 235] The family currently includes 31 Extant taxon, extant, and 10 extinct genera. Distribution Strombid gastropods live mainly in tropical and subtropical waters. These animals are widespread in the Indo-West Pacific, where most species and genera occur. Nearly 40 of the living species that used to belong to the genus ''Strombus'' can be found in the Indo-Pacific region.Abbott, R.T. (1960). "The genus ''Strombus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slug
Slug, or land slug, is a common name for any apparently shell-less Terrestrial mollusc, terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semi-slugs (this is in contrast to the common name ''snail'', which applies to gastropods that have a coiled shell large enough that they can fully retract their soft parts into it). Various Taxonomy (biology), taxonomic families of land slugs form part of several quite different evolutionary lineages, which also include snails. Thus, the various families of slugs are not closely related, despite the superficial similarity in overall body form. The shell-less condition has arisen many times independently as an example of convergent evolution, and thus the category "slug" is Polyphyly, polyphyletic. Taxonomy Of the six orders of Pulmonata, two – the Onchidiacea and Soleoli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snail
A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastropoda that have a coiled gastropod shell, shell that is large enough for the animal to retract completely into. When the word "snail" is used in this most general sense, it includes not just land snails but also numerous species of sea snails and freshwater snails. Gastropods that naturally lack a shell, or have only an internal shell, are mostly called ''slugs'', and land snails that have only a very small shell (that they cannot retract into) are often called ''semi-slugs''. Snails have considerable human relevance, including Snails as food, as food items, as pests, and as vectors of disease, and their shells are used as decorative objects and are incorporated into jewellery. The snail has also had some cultural significance, tending t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
