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Dolichomacrostomidae
DolichomacrostomidaeRieger, R. M. 1971. Die Turbellarienfamilie Dolichomacrostomidae Rieger: II. Teil. Dolichomacrostominae 1. Zool. Jb. Syst. 98:598-703. is a family of small basal free-living flatworms of the clade Macrostomorpha. There are currently about 40 named species in this family.Tyler, S., Schilling, S., Hooge, M., and Bush L. F. (comp.) (2006-2009) Turbellarian taxonomic database. Version 1.5 Description Members of Dolichomacrostomidae are characterized by the presence of a tubular pharynx directed dorsocaudally and having a gland wreath with rhabdite glands. The brain is perforated by the ducts of the frontal glands, and the copulatory apparatus has a common gonopore for both male and female parts, with the female ducts open rostrally and the male ducts obliquely caudally into the common atrium. The male reproductive system has only one testis, which lies in front or at the same level as the ovaries. Ecology and distribution Species of Dolichomacrostomidae are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrostomorpha
Macrostomorpha is a clade of free living flatworms in the group Rhabditophora. Description Species of Macrostomorpha are characterized by having the necks of the viscid gland and releasing gland emerging in a common collar of anchor cell microvilli. They also gave aciliary speratozoa and a pharynx of the simplex coronatus type. Macrostomorpha constitute a basal group in Rhabditophora, showing such plesiomorphic condition as entolecithal eggs and spiral cleavage Cleavage may refer to: Science * Cleavage (crystal), the way in which a crystal or mineral tends to split * Cleavage (embryo), the division of cells in an early embryo * Cleavage (geology), foliation of rock perpendicular to stress, a result of .... Another trait found among members of the clade is the presence of hard stylet in the male copulatory organ. Phylogeny and systematics Originally the clade Macrostomorpha was divided into two groups: Haplopharyngida (containing a single family, Haplopharyngidae) and Mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flatworm
Platyhelminthes (from the Greek language, Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") is a Phylum (biology), phylum of relatively simple bilaterian, Segmentation (biology), unsegmented, soft-bodied invertebrates commonly called flatworms or flat worms. Being acoelomates (having no coelom, body cavity), and having no specialised circulatory system, circulatory and respiratory system, respiratory organ (anatomy), organs, they are restricted to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food can not be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely parasitic groups: Cestoda, Trematod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiobenthos
Meiobenthos, also called meiofauna, are small benthic invertebrates that live in marine or freshwater environments, or both. The term ''meiofauna'' loosely defines a group of organisms by their sizelarger than microfauna but smaller than macrofaunarather than by their taxonomy. This fauna includes both animals that turn into macrofauna later in life, and those small enough to belong to the meiobenthos their entire life. In marine environments there can be thousands of individuals in 10 cubic centimeters of sediment, and counts animals like nematodes, copepods, rotifers, tardigrades and ostracods, but protists like ciliates and foraminifers within the size range of the meiobenthos are also often included. In practice, the term usually includes organisms that can pass through a 1 mm mesh but are retained by a 45 μm mesh, though exact dimensions may vary. Whether an organism will pass through a 1 mm mesh also depends upon whether it is alive or dead at the time o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermaphrodites
A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many taxonomic groups of animals, primarily invertebrates, are hermaphrodites, capable of producing viable gametes of both sexes. In the great majority of tunicates, mollusks, and earthworms, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. Hermaphroditism is also found in some fish species, but is rare in other vertebrate groups. Most hermaphroditic species exhibit some degree of self-fertilization. The distribution of self-fertilization rates among animals is similar to that of plants, suggesting that similar pressures are operating to direct the evolution of selfing in animals and plants. A rough estimate of the number of hermaphroditic animal species is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
