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Salvatoria Clavata
''Salvatoria clavata'' is a species of Annelida in the family Syllidae Syllidae is a family of small to medium-sized polychaete worms. Syllids are distinguished from other polychaetes by the presence of a muscular region of the anterior digestive tract known as the ''proventricle''. Syllid worms range in size from ....The species is similar to '' Brania pusilla'' but is a bit longer measuring in about 2mm to 3mm, individuals in this species can even grow to 10 mm. They have parental care. It has an acrosome shaped like a beaker. Reproduction They reproduce by iteroparous. The species has been classified as androdioecious, they are said to have evolved from gonochoric ancestors. In this species the eggs are fertilized and incubated in the hermaphrodite's pouch. Occurrence The species has a circumglobal distribution. It can be found in the Adriatic Sea, Gulf of Mexico, Aegean Sea, the Red sea, and the Atlantic Ocean. References Syllidae Annelids { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polycha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syllidae
Syllidae is a family of small to medium-sized polychaete worms. Syllids are distinguished from other polychaetes by the presence of a muscular region of the anterior digestive tract known as the ''proventricle''. Syllid worms range in size from to . Most syllids are benthic organisms that transition to a pelagic epitoke for reproduction. They are found in all regions of the ocean, from the intertidal zone to the deep sea, and are especially abundant in shallow water. They are found in a range of habitats, moving actively on rock and sandy substrates, hiding in crevices and among seaweeds, and climbing on sponges, corals, hydrozoans, seagrasses and mangroves. They are generalist feeders. A young Syllid was one of the first worms to be found with pollen from seagrass in its stomach, making it a possible pollinator. '' Syllis ramosa'' was the first polychaete discovered to have a branching body plan. Later, two species of Ramisyllis were discovered to have a branching body plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brania Pusilla
''Brania pusilla'' is a species of marine annelid in the family Syllidae. The original name for the species was ''Exogone pusilla.'' The species has a cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext .... The body can be 1 mm to 2.5 mm long with 28 to 35 segments. It is suggested that parthenogenesis is a normal condition in this species. According to the Encyclopedia of Life the species is simultaneous hermaphroditic. References Syllidae Animals described in 1851 {{annelid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parental Care
Parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. Patterns of parental care are widespread and highly diverse across the animal kingdom.Kokko, H. & Jennions, M.D. (2008) Parental investment, sexual selection and sex ratios. ''Journal of Evolutionary Biology,'' 21, pp.919–948. doi: 10.1111/j.1420-9101.2008.01540.x. There is great variation in different animal groups in terms of how parents care for offspring, and the amount of resources invested by parents. For example, there may be considerable variation in the amount of care invested by each sex, where females may invest more in some species, males invest more in others, or investment may be shared equally. Numerous hypotheses have been proposed to describe this variation and patterns in parental care that exist between the sexes, as well as among species.Gonzalez-Voyer, A. and Kolm, N. (2010). Parental Care and I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrosome
The acrosome is an organelle that develops over the anterior (front) half of the head in the spermatozoa (sperm cells) of many animals including humans. It is a cap-like structure derived from the Golgi apparatus. In placental mammals the acrosome contains degradative enzymes (including hyaluronidase and acrosin). These enzymes break down the outer membrane of the ovum, called the zona pellucida, allowing the haploid nucleus in the sperm cell to join with the haploid nucleus in the ovum. This shedding of the acrosome, or acrosome reaction, can be stimulated ''in vitro'' by substances a sperm cell may encounter naturally such as progesterone or follicular fluid, as well as the more commonly used calcium ionophore A23187. This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry or fluorescence microscopy. This is usually done after staining with a fluoresceinated lectin such as FITC-PNA, FITC-PSA, FITC-ConA, or flu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iteroparous
Semelparity and iteroparity are two contrasting reproductive strategies available to living organisms. A species is considered semelparous if it is characterized by a single reproductive episode before death, and iteroparous if it is characterized by multiple reproductive cycles over the course of its lifetime. Iteroparity can be further divided into continuous iteroparity (primates including humans and chimpanzees) and seasonal iteroparity (birds, dogs, etc.) Some botanists use the parallel terms monocarpy and polycarpy. (See also plietesials.) In truly semelparous species, death after reproduction is part of an overall strategy that includes putting all available resources into maximizing reproduction, at the expense of future life (see § Trade-offs). In any iteroparous population there will be some individuals who die between their first and second reproductive episodes, but unless this is part of a syndrome of programmed death after reproduction, this would not be called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androdioecious
Androdioecy is a reproductive system characterized by the coexistence of males and hermaphrodites. Androdioecy is rare in comparison with the other major reproductive systems: dioecy, gynodioecy and hermaphroditism. In animals, androdioecy has been considered a stepping stone in the transition from dioecy to hermaphroditism, and vice versa. Androdioecy is sometimes referred to as a mixed breeding system with trioecy and gynodioecy. It is a dimorphic sexual system in plants alongside gynodioecy and dioecy. Evolution of androdioecy The fitness requirements for androdioecy to arise and sustain itself are theoretically so improbable that it was long considered that such systems do not exist. Particularly, males and hermaphrodites have to have the same fitness, in other words the same number of offspring, in order to be maintained. However, males only have offspring by fertilizing eggs or ovules of hermaphrodites, while hermaphrodites have offspring both through fertilizing eggs or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonochorism
In biology, gonochorism is a sexual system where there are only two Sex, sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism contrasts with Hermaphrodite, simultaneous hermaphroditism but it may be hard to tell if a species is gonochoric or sequentially hermaphroditic. (e.g. Parrotfish, ''Patella ferruginea''). However, in gonochoric species individuals remain either male or female throughout their lives. Species that reproduce by Thelytokous, thelytokous parthenogenesis and do not have males can still be classified as gonochoric. Terminology The term is derived from Greek language, Greek (''gone'', generation) + (''chorizein,'' to separate). The term gonochorism originally came from German gonochorismus. Gonochorism is also referred to as unisexualism or gonochory. Evolution Gonochorism has Convergent evolution, evolved independently multiple time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adriatic Sea
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to the northwest and the Po Valley. The countries with coasts on the Adriatic are Albania, Bosnia and Herzegovina, Croatia, Italy, Montenegro, and Slovenia. The Adriatic contains more than 1,300 islands, mostly located along the Croatian part of its eastern coast. It is divided into three basins, the northern being the shallowest and the southern being the deepest, with a maximum depth of . The Otranto Sill, an underwater ridge, is located at the border between the Adriatic and Ionian Seas. The prevailing currents flow counterclockwise from the Strait of Otranto, along the eastern coast and back to the strait along the western (Italian) coast. Tidal movements in the Adriatic are slight, although larger amplitudes are known to occur occasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Mexico
The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States; on the southwest and south by the Mexico, Mexican States of Mexico, states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan, and Quintana Roo; and on the southeast by Cuba. The Southern United States, Southern U.S. states of Texas, Louisiana, Mississippi, Alabama, and Florida, which border the Gulf on the north, are often referred to as the "Third Coast" of the United States (in addition to its Atlantic and Pacific Ocean, Pacific coasts). The Gulf of Mexico took shape approximately 300 million years ago as a result of plate tectonics.Huerta, A.D., and D.L. Harry (2012) ''Wilson cycles, tectonic inheritance, and rifting of the North American Gulf of Mexico continental margin.'' Geosphere. 8(1):GES00725.1, first p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegean Sea
The Aegean Sea ; tr, Ege Denizi (Greek language, Greek: Αιγαίο Πέλαγος: "Egéo Pélagos", Turkish language, Turkish: "Ege Denizi" or "Adalar Denizi") is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans and Anatolia, and covers an area of some 215,000 square kilometres. In the north, the Aegean is connected to the Marmara Sea and the Black Sea by the straits of the Dardanelles and the Bosphorus. The Aegean Islands are located within the sea and some bound it on its southern periphery, including Crete and Rhodes. The sea reaches a maximum depth of 2,639m to the west of Karpathos. The Thracian Sea and the Sea of Crete are main subdivisions of the Aegean Sea. The Aegean Islands can be divided into several island groups, including the Dodecanese, the Cyclades, the Sporades, the Saronic Islands, Saronic islands and the North Aegean islands, North Aegean Islands, as well as Crete and its surrounding islands. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Sea
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; Tigrinya: ቀይሕ ባሕሪ ''Qeyih Bahri''; ) is a seawater inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab el Mandeb strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez (leading to the Suez Canal). It is underlain by the Red Sea Rift, which is part of the Great Rift Valley. The Red Sea has a surface area of roughly 438,000 km2 (169,100 mi2), is about 2250 km (1398 mi) long, and — at its widest point — 355 km (220.6 mi) wide. It has an average depth of 490 m (1,608 ft), and in the central ''Suakin Trough'' it reaches its maximum depth of . The Red Sea also has exten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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