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Reproductive System Of Planarians
The reproductive system of planarians is broadly similar among different families, although the associated structures can vary in complexity. All planarians are hermaphrodites, so their reproductive system has a male and a female part. Both parts communicate with the surface of the body via a single opening called gonopore, which is located on the ventral side of the posterior half of the body. Male part of the reproductive system The male part of the reproductive system in planarians has a set of several testicles, distributed throughout the body in two or more rows. They are usually concentrated in the anterior two thirds of the body, although they can reach close to the posterior end. The testicles are connected to a pair of sperm ducts which run posteriorly towards the gonopore. In some groups, the sperm ducts met in their distal part, forming the ejaculatory duct, which then opens in a cavity called “male atrium”. In others, like land planarians, both open in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penis Papilla Of Obama Ladislavii
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do not bear a penis in every animal species, and in those species in which the male does bear a so-called penis, the penises in the various species are not necessarily homologous. The term ''penis'' applies to many intromittent organs, but not to all. As an example, the intromittent organ of most cephalopoda is the hectocotylus, a specialized arm, and male spiders use their pedipalps. Even within the Vertebrata there are morphological variants with specific terminology, such as hemipenes. In most species of animals in which there is an organ that might reasonably be described as a penis, it has no major function other than intromission, or at least conveying the sperm to the female, but in the placental mammals the penis bears the distal part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microplana
''Microplana'' is a genus of land planarian Geoplanidae is a family of flatworms known commonly as land planarians or land flatworms. These flatworms are mainly predators of other invertebrates, which they hunt, attack and capture using physical force and the adhesive and digestive proper ...s found in Europe and Africa. Description Species of the genus ''Microplana'' are characterized by having an elongate, rounded body and generally only two eyes. The copulatory apparatus has a permanent conical penis with a muscular bulbus projecting into a short atrium. A genito-intestinal canal or a bursa copulatrix is usually present, connecting the intestine to the female atrium. Ecology Species of ''Microplana'' are adapted to different habitats. Most species occur in temperate forests, including beech, oak, pine and mixed forests, and seem to prefer neutral to basic soils, with pH values above 6. However, there are species adapted to drier habitats, such as the African savanna. All ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoophora
Neoophora is a group of rhabditophoran flatworms with ectolecithal eggs, i.e., yolk is not present in the egg as in most animals, but rather is secreted by accessory glands called vitellaria or yolk glands. These glands have the same embryonic origin as the ovaries, but usually constitute a separate organ in adult animals. The monophyly of Neoophora is disputed, since some recent molecular studies indicated that the most basal order, Lecithoepitheliata, is more closely related to Polycladida The Polycladida represents a highly diverse clade of free-living marine flatworms. They are known from the littoral to the Sublittoral zone, sublittoral zone (extending to the deep hot vents), and many species are common from coral reefs. Only a ..., a non-neoophoran order, than to other neoophorans. This would imply that the ectolecithal condition would have evolved twice. The clade formed by all other neoophorans, excluding Lecithoepitheliata, is usually called Euneoophora. Referenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yolk
Among animals which produce eggs, the yolk (; also known as the vitellus) is the nutrient-bearing portion of the egg whose primary function is to supply food for the development of the embryo. Some types of egg contain no yolk, for example because they are laid in situations where the food supply is sufficient (such as in the body of the host of a parasitoid) or because the embryo develops in the parent's body, which supplies the food, usually through a placenta. Reproductive systems in which the mother's body supplies the embryo directly are said to be matrotrophic; those in which the embryo is supplied by yolk are said to be lecithotrophic. In many species, such as all birds, and most reptiles and insects, the yolk takes the form of a special storage organ constructed in the reproductive tract of the mother. In many other animals, especially very small species such as some fish and invertebrates, the yolk material is not in a special organ, but inside the egg cell. As sto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oviduct
The oviduct in mammals, is the passageway from an ovary. In human females this is more usually known as the Fallopian tube or uterine tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, or will degenerate in the body. Normally, these are paired structures, but in birds and some cartilaginous fishes, one or the other side fails to develop (together with the corresponding ovary), and only one functional oviduct can be found. Except in teleosts, the oviduct is not directly in contact with the ovary. Instead, the most anterior portion ends in a funnel-shaped structure called the infundibulum, which collects eggs as they are released by the ovary into the body cavity. The only female vertebrates to lack oviducts are the jawless fishes. In these species, the single fused ovary releases eggs directly into the body cavity. The fish eventually extrudes the eggs through a small genital pore towards the rear of the body. Fish and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovary
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. The ovaries also secrete hormones that play a role in the menstrual cycle and fertility. The ovary progresses through many stages beginning in the prenatal period through menopause. It is also an endocrine gland because of the various hormones that it secretes. Structure The ovaries are considered the female gonads. Each ovary is whitish in color and located alongside the lateral wall of the uterus in a region called the ovarian fossa. The ovarian fossa is the region that is bounded by the external iliac artery and in front of the ureter and the internal iliac artery. This area is about 4 cm x 3 cm x 2 cm in size.Daftary, Shirish; Chakravarti, Sudip (2011). Manual of Obstetrics, 3rd Edition. Elsevier. pp. 1-16. . The ovari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notogynaphallia
''Notogynaphallia'' is a genus of land planarians from South America. Description The genus ''Notogynaphallia'' is characterized by having a small-to-medium, slender body with nearly parallel margins. The eyes are arranged along the body margins and may or not spread to the dorsum. The copulatory apparatus lacks a permanent penis, i. e., the penis is formed during copulation by folds in the male atrium. The male part of the copulatory apparatus also lacks an ejaculatory duct, so that the prostatic vesicle opens directly into the male atrium. The female atrium is usually irregular and narrow and the ovovitelline ducts join each other behind it. Etymology The name ''Notogynaphallia'' comes from Greek ''νότος'' (back) + ''γυνή'' (female) + ''ἀ'' (without) + ''φαλλός'' (phallus, penis), i.e., "dorsal female without penis", referring to ovovitelline ducts entering the female atrium dorsally and the absence of a permanent penis. Species The following species a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luteostriata
''Luteostriata'' is a genus of land planarians from Brazil characterized by a yellow body with dark longitudinal stripes. Description The genus ''Luteostriata'' is characterized by the presence of a cephalic retractor muscle, which allows those animals to pull their anterior end upwards and backwards. Associated to the muscle are cephalic glands, forming a so-called cephalic musculo-glandular organ in a way similar to the one found in the genera ''Choeradoplana'' and '' Issoca''. The copulatory apparatus has an reversible penis, i.e., there is no permanent penis papilla and the penis is formed during copulation by folds in the male cavity which are pushed outwards. Externally, species in this genus usually have a yellow to light brown dorsal color with a series of longitudinal dark stripes, hence the name ''Luteostriata'', from Latin ''luteus'' (saffron yellow) + ''striatus'' (striped). The anterior end is also usually marked by an orange tinge that posteriorly gradually fades ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imbira
''Imbira'' is a genus of land planarians found in South America. Description The genus ''Imibira'' is characterized by having a large, slender and flat body with parallel margins, reaching up to 14 cm in length. The eyes are arranged along the body margins, not occupying the dorsum. In comparison to other genera, the body has an additional layer of longitudinal muscles dorsally and ventrally to the intestine. The copulatory apparatus lacks a permanent penis, i. e., the penis is formed during copulation by folds in the male cavity. The female cavity is rounded and filled with a multilayered epithelium. Etymology ''Imbira'' is a word in the Tupi language that refers to a strip of bark peeled off from certain trees. Species There are four species assigned to the genus ''Imbira'': *''Imbira flanovigra'' Amaral & Leal-Zanchet, 2018 *''Imbira guaiana'' (Leal-Zanchet & Carbayo, 2001) *''Imbira marcusi'' Carbayo et al., 2013 *''Imbira negrita ''Imbira'' is a genus of lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasipha
''Pasipha'' is a genus of land planarians from South America. Description Species of the genus ''Pasipha'' have a slender and flattened body with parallel margins while creeping. The copulatory apparatus lacks a permanent penis, having a long and highly folded male atrium instead. The prostatic vesicle is located outside the muscular coat of the copulatory apparatus and divided in two portions. The female canal enters the genital antrum ventrally. Species The following species are recognised in the genus ''Pasipha'': *'' Pasipha albicaudata'' *'' Pasipha aphalla'' *'' Pasipha astraea'' *'' Pasipha atla'' *''Pasipha backesi'' *'' Pasipha brevilineata'' *'' Pasipha caeruleonigra'' *'' Pasipha cafusa'' *''Pasipha carajaensis'' *'' Pasipha chilensis'' *'' Pasipha chimbeva'' *''Pasipha diminutiva'' *''Pasipha ercilla'' *''Pasipha ferrariaphila'' *''Pasipha hauseri'' *''Pasipha johnsoni'' *''Pasipha liviae'' *''Pasipha mbya'' *''Pasipha mesoxantha'' *''Pasiph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choeradoplana Minima
''Choeradoplana'' is a genus of land planarians found in South America. Description Species of the genus ''Choeradoplana'' are characterized by the presence of a cephalic retractor muscle associated with cephalic glands, forming a cephalic musculo-glandular organ in a way similar to the one found in the genera ''Luteostriata'' and '' Issoca''. The head of ''Choeradoplana'' is highly rolled backwards and the ventral area thus visible has two "cushions" formed by the musculo-glandular organ.Ogren, R. E. and Kawakatsu, M. (1990). ''Index to the species of the family Geoplanidae (Turbellaria, Tricladida, Terricola) Part I: Geoplaninae.'' Bulletin of Fujis Women's College. 29: 79-166. This peculiar head shape makes it easy to identify a species as belonging to this genus. Etymology The name ''Choeradoplana'' comes from Greek word ''χοιράς'' ( scrofula) and the Latin word ''plana'' (flat) due to the two cushions on the ventral side of the head that resemble the neck swellings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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