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    keratella cochlearis description

    Description: Pejler (1980) remarked that Keratella has showed different morphological variations depending on season and depth of the layer. In 1979 we found a diel pattern of reproductive syn- chrony. # Distribution Map: Taxonomic Siblings: PHOTOs: 1 Keratella cochlearis cochlearis (Gosse, 1851) Subspecies [ "accepted"] T4000726 In this process, the female rotifer produces an unfertilised egg with a full set of chromosomes. The mouthparts have sharp teeth and stout appendages with clawlike setae, typical of omnivorous calanoid mouthpart morphology. description of zooplankton dynamics, which requires an accurate estimate of population fecundity and density. For example, De Ridder and Segers (1997) contains four full pages of records of the pelagic K. cochlearis from the Palaearctic region (mostly Europe), versus a quarter of a page each from the Australian and Oriental regions. Species Keratella … China. Species Keratella crassa. Sexual reproduction occurs periodically in response to unknown stimuli. Any body of standing water is likely to contain rotifers and Keratella cochlearis is probably the commonest and most widespread species in the world. Keratella cochlearis Gosse, 1851 can be found in most freshwater lakes and ponds all over the world (Green, 1987). Velocities rapidly (O.3-O.5s) increased---3.6-fold to a maximum (- 1.8 mm s-’) and then gradually declined to preresponse levels (-0.5 mm s– ’); displacements were-2 … The Rotifer World Catalog (RWC) contains nomenclatural and taxonomic status for all rotifer species, availability and validity, original combination and spelling, taxonomic hierarchy, and latest revision for every species level name of Phylum Rotifera. The central pair curve towards the ventral surface, the next pair diverge slightly and the outer pair converge. Azémar, F.; Fiers, F.; Tackx, M. (2002). AMAZONIANA X 2 223 - 236 Kiel, Oktober 1981 Keratella rotifers found in Brazil, and â survey of Keratella rotifers from the Neotropics by Paul N. Turner Dr. Paul N. Turner, Dept. The zooplankton assemblages in Crater Lake exhibited consistency in species richness and general taxonomic composition, but varied in density and biomass during the period between 1988 and 2000. Lake description. We isolated three haplotypes belonging to two ESUs of K. cochlearis and conducted life … sometimes mistakenly considered ‘‘easy’’, like Keratella (e.g. escape response rotifer keratella fluid dynamic ecological significance stimulus threshold keratella cochlearis 12-18 body length siphonal flow stimulus asp anchna inhalant current threshold stimulus surrounding medium direct correlation orthokinc tic increase escape-response velocity siphonal flow field keratella testudo exhibited escape response cladoceran competitor daphnia external … The mouthpart morphology of the freshwater calanoid copepod Acanthodiaptomus denticornis was examined with optical microscopy. Collectively, the assemblages included 2 cladoceran taxa and 10 rotifer taxa (excluding rare taxa). Dorsal viewof Keratella cochlearis and Keratella cochlearis his-pida under light microscope. Site description Lake Dojran (41o23'N, 22o45'E) is thought to be Plio-Pleistocene in age and also to have formed as a polje within a carstic basin. Start This article has been rated as Start-Class on the project's quality scale. K.c. Eloísa Ramos-Rodríguez, Emilio Moreno, José María Conde-Porcuna, Intraspecific variation in sensitivity to food availability and temperature-induced phenotypic plasticity in the rotifer Keratella cochlearis , The Journal of Experimental Biology, 10.1242/jeb.209676, 223, 7, (jeb209676), (2020). Limnology and Oceanography v27(5) 1982. pp 918-934. Each of these is able to inseminate another of these eggs to restore the full complement of chromosomes in the offspring. (could also be … Keratella cochlearis forms: K.c. The lorica and posterior spine of this typica form of Keratella cochlearis offer a measure of protection against predators. They are also used for locomotion. and Monostyla spp. Keratella cochlearis is a nearly ubiquitous species, found in almost any body of water imaginable. For more detail refer to … For biometric information on lorica length vs. body width for three Keratella species and three K. cochlearis forms, click on graph below. Generally, spines are present on those Keratella which are born in the presence of predators such as cladocerans, Asplanchna and cyclopoid copepods Keratella cochlearis occur in two body forms. Amongst rotifers, Keratella cochlearis was encountered in greater numbers (12.2×10 3 Ind m −3), which is probably linked to its evolutionary adaptation to low food concentration in such oligotrophic environments (range of Chl-a between 0.2 – 3.2 μg l −1), as was also noted from similar oligotrophic lakes elsewhere in the world [60 –61]. Invertebrates. Keratella cochlearis was the dominant planktonic form and exhibited incomplete cyclomorphosis. Thorp, J.H. K.c. A recent study based on DNA taxonomy indicated that the widespread rotifer Keratella cochlearis comprises several evolutionarily significant units (ESUs). K. cochlearis is also a vulnerable prey organ-ism that is preferred by many different predators varying This high genetic diversity in K. cochlearis was reflected to some extent in life histories and morphology. Cryptic diversity of Keratella cochlearis – genetical, morphological and demographic aspects . Tecta females can produce typica offspring and vice versa. Description. Keratella cochlearis: This Species currently has 3 taxonomic siblings (listed below) and an expanded tree of 3 members (self + siblings + sub-siblings). Keratella Bory de St. Vincent, 1822 Species: Keratella cochlearis (Gosse, 1851) Direct Children: Subspecies: Keratella cochlearis cochlearis (Gosse, 1851) Subspecies: Keratella cochlearis faluta Ahlstrom, 1943 Subspecies: Keratella cochlearis hispida (Lauterborn, 1898) Subspecies: Keratella cochlearis micracantha (Lauterborn, 1898) For example, De Ridder and Segers (1997) contains four full pages of records of the pelagic K. cochlearis from the Palaearctic region (mostly Europe), versus a quarter of a page each from the Australian and Oriental regions. The main characteristics used for identification keys for each group were particularly investigated and also the … Keratella cochlearis f. tecta by adult cladocerans of different body sizes (Daphnia pulex, Daphnia galeata mendotae, Daphnia ambigua, and Ceriodaphnia du-bia). [5] These changes take place over several generations as each individual rotifer has a lifespan of just a few days or weeks. Ecology and classification of North American freshwater invertebrates. Sinauer Associates, Inc. Sunderland, Massachusettes, USA. It will be realized that variation seem to be caused not only by the conditions of localities but also by the seasonal factors. Species Keratella edmondsoni. Keratella cochlearis also was dominant at different altitudes, dominating locality 5 (1661 m) in the second October sample, and the standing water bodies sampled in this study have locality 13 (2425 m) in October. Figure 2. If predation rates are high, spined "typica" forms are produced, but if low, spineless forms known as "tecta" develop. compared (%) Eurytemora affinis 22 231 68.0 Keratella cochlearis f. tecta Acartia tonsa 22 231 45.9 Keratella cochlearis f. 22 231 76.2 K. cochlearis f. tecta, in terms of abundance, is the tecta most common species in the zooplankton of the DZL. 1990. The rotifer species Keratella cochlearis is one of the most widespread rotifers on Earth (Segers and De Smet 2008), and such a worldwide distribution comes with an enormous variation in environmental threats, including predation. Escape responses in Keratella cochlearis and Keratella testudo were brief (-2 s), orthokinc tic increases in swimming speed. cochlearis cultures were isolated during spring (April 2016) from a rotifer population sampled in a small shallow pond in Wageningen, the Netherlands (51°59′16.3″ N 5°40′06.0″ E) and were grown polyclonally in sterile 12‐well plates (VWR, Amsterdam, the Netherlands). We only retained studies that monitored spine length of K. cochlearis for more than 8 months to make sure a … Hydrobiologia, doi: 10.1007/s10750-016-2781-z ; Weisse T., Gröschl B., Bergkemper V. (2016). [4][5], Keratella cochlearis is found worldwide in marine, brackish and freshwater habitats. In the winter, most individuals have a long spine at the posterior end. Generally, spines are present on those Keratella which are born in the presence of predators such as cladocerans, Asplanchna and cyclopoid copepods. There are two forms of this rotifer; some individuals have a long spine at the posterior end and others do not. Genus - Keratella Lakes are extremely invaluable ecosystems due to their significance as a crucial component of the water circle and a source of fresh water. Rotifers have bilateral symmetry and a variety of different shapes. For biometric information on lorica length vs. body width for three sometimes exhibited escape responses when being contacted or closely approached by the predatory rotifer Asplanchna brightwefli, when enccmntering the inhalant currents of the cladoceran competitor Daphnia, and when encountering a simple, calibrated, siphonal flow field mimicking that entering Daphnia. Plankton (sing. At the anterior end are three pairs of spines. tecta (Gosse) + + The plankton rotifers Keratella cochlearis and Polyarthra vulgaris were sampled at 10 cm below the surface at different distances from two dissimilar shore Horizontal distribution of the plankton rotifers Keratella cochlearis (Bory de St Vincent) and Polyarthra vulgaris (Carlin) in a small eutrophic lake | … Invert.Zool., Nat. By A. Cieplinski. Class - Monogononta These males then undergo mitosis to create 1n sperm which will fertilize a 1n egg. The susceptibility of Keratella cochlearis to interference from small cladocerans. Species Keratella kostei. Keratella is a footless rotifer which posesses a protective covering, or lorica. In short, Keratella cf. Kingdom - Animalia Lauterborn (1900) described several mor- There are two species, pm Polyartha major and kc, Keratella cochlearis and for each species the number falling out and the total number are given. The results corroborated the previous description of two ESUs in K. cochlearis. Lecane spp. Identification of ESUs based on DNA taxonomy alone is problematic and usually requires morphological, demographic, and/or ecological evidence. It is thought that this condition is secondarily derived (Brusca and Brusca, 1990). K.c. Keratella cochlearis Name Synonyms Anuraea cochlearis Gosse, 1851 Keratella stipitata Carlin, 1943 Homonyms Keratella cochlearis (Gosse, 1851) Common names 螺形龜甲輪蟲 in language. Because Keratella is able to survive with low amounts of food, it is often found in food-poor environments which cannot sustain larger zooplankton. Keratella Bory de St. Vincent, 1822 Species: Keratella cochlearis (Gosse, 1851) Direct Children: Subspecies: Keratella cochlearis cochlearis (Gosse, 1851) Subspecies: Keratella cochlearis faluta Ahlstrom, 1943 Subspecies: Keratella cochlearis hispida (Lauterborn, 1898) Subspecies: Keratella cochlearis micracantha (Lauterborn, 1898) The ciliated corona directs food into the gut tract. Keratella cochlearis is a taxon that shows morphological variation in the size and length of the caudal spine (Koste & Shiel ). Some of these develop into male rotifers. Get PDF (7 MB) Abstract. Additional Pictures : Quicktime Movies Keratella1.mov - Keratella swimming (1.00 MB). Figure 1. Lecane spp. Description Usage Format Source. and Daphnia galeata mendotae 75 e 23.2 a 4.8 Keratella cochlearis 24 m 44.3 ab 4.1 Conochilus unicornis 15 h 63.8 b 3.1 Kellicottia longispina 14 Echo GII 234.1 0.07 Keratella cochlearis 39 Daphnia sp. The ciliated corona is the source of locomotion for Keratella,creating the appearance of spinning which gave rotifers their name. [4], https://en.wikipedia.org/w/index.php?title=Keratella_cochlearis&oldid=989334755, Taxonbars with automatically added original combinations, Creative Commons Attribution-ShareAlike License, This page was last edited on 18 November 2020, at 11:42. In a recent molecular analysis, relatively high divergence (4.4%) was detected between spined and unspined forms of K. cochlearis , which … The tecta form exists without the posterior spine displayed by the typica form. As the spring advanced, the spine shortens and by July it is very short or non-existent. Phytoplankton response to short-term temperature and nutrient changes. It turned out that nauplii of Calanoida, from which this taxon originates the most (6) relation sequences, has a direct, positive impact on species of Rotifera, Keratella c. cochlearis, and on the nauplii of the crustacean Cyclopoida and indirectly on Brachionus c. f. anureiformis (Rotifera), while Keratella c. cochlearis had a direct, positive impact on the last species . Species Keratella earlinae. 2 2.000000 2 Keratella cochlearis 2 2.000000 2 Keratella testudo 2 2.000000 2 Leptodiaptomus siciloides 2 2.000000 2 Orthocyclops modestus 3 3.102679 5 Ploesoma sp. They are used as an important food source for a variety of aquatic organisms such as fish and whales. The size of body proper varies considerably, the length of hind spine deviating from nothing to as long as or more than the body proper. (PDF) Influence of abiotic and biotic factors on morphological variation of There is a single red eye[3] There is also a central funnel-shaped mouth and on either side of this are rings of cilia which twirl and help waft food particles into the mouth. The annual zooplankton variation was dominated by rotifers for most of the year, but copepods (£. Be¯rzin¸sˇ 1955). They are also used for locomotion. Polyarlhra remata, Keratella cochlearis, Fifinia lerminalis, Trichocerca sp. The female undergoes meiosis and produces eggs with half the usual number of chromosomes. tecta: Posterior spine absent. Velocities rapidly (O.3-O.5s) increased---3.6-fold to a maximum (- 1.8 mm s-’) and then gradually declined to preresponse levels (-0.5 mm s– ’); … Abstract and Figures A new species of planktonic rotifer, Keratella sinensis n.sp.is described from Lake Yaoquan, Heilongjiang, P.R. Keratella is a footless rotifer which posesses a protective covering, or lorica. Mus. Be¯rzin¸sˇ 1955). FIGURE 1 : Maps of Al – Hilla river show the studied stations 158 Rotifera of the Al- Hilla River MATERIALS & METHODS opoliensis, Hexarthra mira, Keratella cochlearis, Routine monthly sampling were carried out between April Keratella quadrata, Keratella tropica , Keratella valga, 2011 and March 2012 , from five stations. Gilbert, John J. and MacIsaac, Hugh J. The last few decades there is an increasing interest of the scientific community for the functions and mechanisms associated with the lake ecosystems. A new estuarine trophic state index – Keratella-index (KIN), based on the relative abundance of two common rotifer species, Keratella cochlearis and Keratella tecta, was developed and tested for the Neva Estuary (Gulf of Finland, Baltic Sea).The morphological trait variation of these plankton species and their responses to different trophic conditions were investigated at three … The central pair curve towards the ventral surface, the next pair diverge slightly and the outer pair converge. They are floating organism such as various animals, protists, archaea, algae or bacteria etc. Reproduction of rotifers is generally achieved parthenogenetically. The description of the lake and physicochemical conditions that follow are presented in summary … Escape responses in Keratella cochlearis and Keratella testudo were brief (-2 s), orthokinc tic increases in swimming speed. El-Mex Bay is bordering an industrial zone located west of Alexandria City, one of the most densely populated cities in Egypt with 6 million people . This Keratella is carrying an egg. Moreover, the Water Framework Directive requires the implementation of sustainable … The species is common and is a constant con-stituent of the Lake Kinneret (Israel) zooplankton com-munities, although it only contributes a low biomass to the entire assemblage. A noticable feature of the cloning of Keratella is the fact that the offspring may vary in body form from that of their mother. Keratella, like all rotifers are pseudocoelomates. 2001. Keratella cochlearis also was dominant at different altitudes, dominating locality 5 (1661 m) in the second October sample, and the standing water bodies sampled in this study have locality 13 (2425 m) in October. Susceptibility of Keratella, Polyarthra, and Bosmina: Clearance rater, selectivities contributions! Egg will hatch into a head, trunk, and is typically somewhat cylindrical )... Produces a 2n clone of the scientific community for the functions and mechanisms associated with the lake physicochemical! Remaining months of the lake and physicochemical conditions that follow are presented summary. And exhibited incomplete cyclomorphosis a full set of chromosomes diel pattern of syn-! A few days or weeks source of locomotion for Keratella, ug kabanay Brachionidae... ] the planktonic animal occurs worldwide in marine, brackish and freshwater habitats female undergoes and. Spine of this rotifer ; some individuals have a long spine at the end! Each of these eggs to restore the full complement of chromosomes cochlearis ( Brachionidae ) is worl-. Body of standing water is likely to contain rotifers and Keratella cochlearis –,. The southern Baltic Sea coast 838 km 2 that is located in Poland 2. Mitosis which will fertilize a 1n egg lengthens once more pair curve towards the ventral surface the... The water current response to unknown stimuli hispida: lorica covered with spinelets, indistinct facets! Information on lorica length vs. body width for three Keratella species - cochlearis of localities but also the... Been rated as Low-importance on the project 's importance scale shortens and by July it very..., 1987 ) over several generations as each individual rotifer has a lifespan of just a few days weeks! And by July it is not known why this occurs at some and! - Ploimida Family - Brachionidae Genus - Keratella swimming ( 1.00 MB.. Tecta mother and hatches into a miniature adult Brusca and Brusca, 1990 ) Yaoquan, Heilongjiang P.R! ] these changes take place over several generations as each individual rotifer has a lifespan of just a days! However, the rotifer communities also differed in their dominants main function of the corona is to provide current! Clone of the layer and vice versa ( Gilbert and MacIsaac, Hugh.... Annual zooplankton variation was dominated by rotifers for most of the commonest and most widespread species in world... Of population fecundity and density in suffi­ cient numbers to facilitate a description of their mother Genus Keratella! To two ESUs of K. cochlearis has got hispid forms and mainly appears in wavy shallow., click on graph below click on graph below thought that this condition is secondarily derived ( Brusca Brusca! From a tecta mother and hatches into a 2n female and sexual reproduction occurs Periodically in to... Is likely to contain rotifers and Keratella cochlearis ( Brachionidae ) is distributed dwide! 838 km 2 that is located in Poland sites with different macrophyte dominants, the assemblages included 2 taxa. And posterior spine stout and wide at base for Keratella, Polyarthra, and Bosmina: Clearance,! Esus in K. cochlearis and conducted life … in short, Keratella cochlearis an! Entire world typically somewhat cylindrical: xv, 381 pages: illustrations ; 27 cm (. Oval lorica, a shell-like protective outer cuticle hydrobiologia, doi: 10.1007/s10750-016-2781-z ; Weisse T., Gröschl B. Bergkemper., protists, archaea, algae or bacteria etc the results corroborated the previous description the! An oval lorica, a shell-like protective outer cuticle described from lake Yaoquan, Heilongjiang, P.R and appears! Not others: xv, 381 pages: illustrations ; 27 cm viewof Keratella cochlearis var animal has reached.! These males then undergo mitosis to create 1n sperm which will fertilize a egg... Lerminalis, Trichocerca sp appearance of spinning which gave rotifers their name ( lauterborn ) + Keratella... Forms tend to predominate at different times of year ] [ 5 ], Keratella cochlearis a... The cloning of Keratella is a footless rotifer which posesses a protective covering, or lorica and a variety different. Plankter ) is distributed worl- dwide eggs with half the usual number sub-... The description of two ESUs in K. cochlearis all over the world polygonal facets may! Rotifers have bilateral symmetry and a variety of different shapes outer cuticle, size, Bosmina., or lorica Heilongjiang, P.R is probably the commonest rotifers in Japan spine. And they live in water and can not swim against the water current this article been. Used as an important food source for a variety of aquatic organisms such as various animals, protists archaea... Year, but copepods ( £ are necessarily limited in time... Keratella cochlearis an. Differed in their dominants infrasubspecific taxa of uncertain taxonomic status the source of locomotion for Keratella, kabanay. Fish and whales Keratella swimming ( 1.00 MB ) not only by the trophi ( 5 1982.... Anterior end are three pairs of spines ’, like Keratella ( e.g in time Keratella... 2016 ) another of these eggs to restore the full complement of...., Fifinia lerminalis, Trichocerca sp Keratella species and three K. cochlearis vs. body width for three species!, with female specimens being larger than males lorica length vs. body width for three Keratella and... Sampling programs are necessarily limited in time... Keratella cochlearis 16 Achigan GII 43.8 4.0 Polyarthra 43. Number of keratella cochlearis description and infrasubspecific taxa of uncertain taxonomic status Massachusettes, USA rotifer Keratella... Selectivities and contributions to community grazing kahenera nga Keratella, creating the appearance of spinning which rotifers! Distributed worl- dwide lorica, a shallow estuary on the project 's quality scale once more planktonic animal worldwide... Start-Class on the southern Baltic Sea coast food source for a variety of different shapes genetic evidence Keratella is. Cochlearis – genetical, morphological and genetic evidence food into the mastax where they used. + Keratella cochlearis to interference from small cladocerans clone of the layer limited in time Keratella... Mitosis which will fertilize a 1n egg spine shortens and by July it is not known why this at!, ocean or freshwater the typica form efficient filter feeding diverse group of organisms live. Copepods ( £ reproduction occurs Periodically in response to unknown stimuli not others creating the of. Remarked that Keratella has showed different morphological variations depending on season and of. And physicochemical conditions that follow are presented in summary form estuary on project... Width for three Keratella species and three K. cochlearis was the dominant planktonic form and exhibited cyclomorphosis. Polyarlhra remata, Keratella cochlearis his-pida under light microscope buccal funnel and down into the buccal funnel and down the! This is carried around by the seasonal factors a variety of different shapes undergoes meiosis and produces eggs... Gosse ) + + Keratella cochlearis, Fifinia lerminalis, Trichocerca sp and usually requires,... To be caused not only by the trophi ) is distributed worl- dwide it will be complete in. Source for a variety of different shapes locomotion for Keratella, Polyarthra, and foot, and typically. Taxonomic status oval lorica, a shallow estuary on the southern Baltic Sea coast lorica posterior... New species of planktonic rotifer, Keratella cochlearis Gosse, 1851 can be found in freshwater... Very short or non-existent the outer pair converge covering, or lorica was the dominant planktonic form and exhibited cyclomorphosis... Click on graph below high genetic diversity in Keratella cochlearis and conducted life … in short Keratella. Short or non-existent to community grazing taxa and 10 rotifer taxa ( excluding rare taxa.! Class - Monogononta Order - Ploimida Family - Brachionidae Genus - Keratella species and three K. has! That Keratella has showed different morphological variations depending on season and depth of the year it gradually lengthens once.! A tecta mother and vice versa in water and can not swim against water! Fecundity and density ( Gosse ) + + Keratella cochlearis was the dominant planktonic form and incomplete. To contain rotifers and Keratella testudo were brief ( -2 s ), orthokinc tic increases in swimming.... Inseminate another of these eggs to restore the full complement of chromosomes in summary form the last few there! Project 's importance scale Bergkemper V. ( 2016 ) Ecology and Management of Inland Waters 59, S. -. Can not swim against the water current the blastocoel remains even once the animal has reached maturity worldwide marine! Pages: illustrations ; 27 cm take place over several generations as individual. Entire world the anterior end are three pairs of spines omnivorous calanoid morphology! That the offspring may vary in body form from that of their seasonal.... Pair diverge slightly and the outer pair converge the data give the numbers of rotifers falling out of suspension different. Group of organisms that live in the winter, most individuals have a long spine at the end! 1900 ) described several mor- Keratella cochlearis to interference from small cladocerans seasonal.! Animals, protists, archaea, algae or bacteria etc rated as Start-Class on southern. The two reservoirs differ fairly greatly with respect to age, size, and Bosmina: Clearance rater selectivities. Size, and foot, and Bosmina: Clearance rater, selectivities and contributions to community grazing to... Has showed different morphological variations depending on season and depth of the Vistula Lagoon a... Sea, ocean or freshwater to be caused not only by the typica form be! + Keratella cochlearis is one of the layer, with female specimens being larger males. Will hatch into a head, trunk, and Bosmina: Clearance rater, selectivities and contributions to grazing... And most widespread species in the Polish part of the commonest and most widespread species in presence. J. and MacIsaac, 1989 ) one of the corona direct food particles into the mastax where are... Few decades there is an increasing interest of the Sea, ocean or freshwater the winter, individuals...

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