Hydrozoa (hydrozoans, from ancient Greek ὕδρα, hydra, "sea serpent" and ζῷον, zoon, "animal") are a taxonomicclass of individually very small, predatory animals, some solitary and some colonial, most living in salt water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in fresh water. Hydrozoans are related to jellyfish and corals and belong to the phylumCnidaria.
Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. For example, Hydra has no medusoid stage, while Liriope lacks the hydroid stage.
Polyps
The hydroid form is usually colonial, with multiple polyps connected by tubelike hydrocauli. The hollow cavity in the middle of the polyp extends into the associated hydrocaulus, so that all the individuals of the colony are intimately connected. Where the hydrocaulus runs along the substrate, it form a horizontal root-like stolon that anchors the colony to the bottom.
Actinula release in Ectopleura crocea (Cnidaria, Hydrozoa, Tubulariidae)
Hydrozoan Life Cycle
Ectopleura crocea (Cnidaria, Hydrozoa, Hydroidolina, Anthoathecata, Aplanulata, Tubulariidae) is a common marine hydroid in the Atlantic ocean, usually abundant on artificial substrates. They form dense tufs with hundreds of individuals, which hydrocaulli are up to 10-12 cm long. The species doesn't have a medusa in its life cycle, and gametes are produced within structures called gonophores, which stay fixed to the polyp body. Individuals are either male or female. Spermatozoa are released into the water from male gonophores, fertilizing the eggs that remain within female gonophores. Embryos develop inside female gonophores into actinula larvae, the dispersive stage of the species. A mature female polyp releases hundreds of actinulae. As you may see in the video, the...
published: 12 Aug 2014
Cnidaria, Medusozoa, Hydrozoa
published: 22 Jul 2020
Cnidaria - Class Hydrozoa
published: 18 Sep 2020
Hydras: Our Immortal, Tentacled Friends
While humans age and die (which is kind of a bummer), it looks like hydras will stay young and fertile forever. Why is this? And what can we learn from these tentacular microscopic organisms?
Hosted by: Hank Green
----------
Dooblydoo thanks go to the following Patreon supporters -- we couldn't make SciShow without them! Shout out to Justin Ove, Chris Peters, Philippe von Bergen, Fatima Iqbal, John Murrin, Linnea Boyev, Justin Lentz, and David Campos.
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published: 11 Dec 2015
Class Hydrozoa | Classification of Phylum Cnidaria
KHANTECH Education has brought you lecture of Anum Ejaz on "Biology | Class Hydrozoa | Classification of Phylum Cnidaria".
#Biology #Phylum_Cnidaria #hydrozoa #classification #khantech_education
Phylum cnidaria is divided into three classes:
Anthozoa
Hydrozoa
Scyphozoa
CLASS HYDROZOA
Hydrozoans are small relatively common cnidarians. The vast majority are marine, but this is the one cnidarian class with freshwater representative.
HYDROZOA Cnidaria with polyp dominant.
One of the few fresh water cnidaria.
They are also found in attached to underwater plant or rocks, mostly in lakes and ponds.
Three features distinguish hydrozoans from other cnidarians:
Nematocyst are only in the epidermis.
Gametes are epidermal and are release at the outside of the body rather than into the gastr...
Hydrozoan Life Cycle
Ectopleura crocea (Cnidaria, Hydrozoa, Hydroidolina, Anthoathecata, Aplanulata, Tubulariidae) is a common marine hydroid in the Atlantic o...
Hydrozoan Life Cycle
Ectopleura crocea (Cnidaria, Hydrozoa, Hydroidolina, Anthoathecata, Aplanulata, Tubulariidae) is a common marine hydroid in the Atlantic ocean, usually abundant on artificial substrates. They form dense tufs with hundreds of individuals, which hydrocaulli are up to 10-12 cm long. The species doesn't have a medusa in its life cycle, and gametes are produced within structures called gonophores, which stay fixed to the polyp body. Individuals are either male or female. Spermatozoa are released into the water from male gonophores, fertilizing the eggs that remain within female gonophores. Embryos develop inside female gonophores into actinula larvae, the dispersive stage of the species. A mature female polyp releases hundreds of actinulae. As you may see in the video, the actinula larva struggles to get free from the gonophore. It pushes several times using its tentacles; it succeeds in liberating one tentacle at a time, until it finally got out through the aperture of the gonophore. It took about 2 hours for the actinula shown in the video (time-lapse) to get free, but this period may vary a lot. The actinula settles by its aboral end and elongates to form a juvenile polyp. It may settle on the perisarc of adults, as is seen in the video. Newly released actinulae have aboral tentacles and rudiments of oral tentacles.
References:
Imazu, M.A., Ale, E., Genzano, G.N. & Marques, A. C. 2014. A comparative study of populations of Ectopleura crocea and Ectopleura ralphi (Cnidaria, Hydrozoa, Tubulariidae) from the Southwestern Atlantic Ocean. Zootaxa 3753 (5): 421–439.
More images of hydroids and marine beings at http://cifonauta.cebimar.usp.br/
Support
CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico, Edital MCT/CNPq nº 42/2007 - Difusão e Popularização da C&T (processo nº 551951/2008-7).
Centro de Biologia Marinha, Universidade de São Paulo
http://cebimar.usp.br/index.php/pt/
https://www.facebook.com/cebimarusp
Hydrozoan Life Cycle
Ectopleura crocea (Cnidaria, Hydrozoa, Hydroidolina, Anthoathecata, Aplanulata, Tubulariidae) is a common marine hydroid in the Atlantic ocean, usually abundant on artificial substrates. They form dense tufs with hundreds of individuals, which hydrocaulli are up to 10-12 cm long. The species doesn't have a medusa in its life cycle, and gametes are produced within structures called gonophores, which stay fixed to the polyp body. Individuals are either male or female. Spermatozoa are released into the water from male gonophores, fertilizing the eggs that remain within female gonophores. Embryos develop inside female gonophores into actinula larvae, the dispersive stage of the species. A mature female polyp releases hundreds of actinulae. As you may see in the video, the actinula larva struggles to get free from the gonophore. It pushes several times using its tentacles; it succeeds in liberating one tentacle at a time, until it finally got out through the aperture of the gonophore. It took about 2 hours for the actinula shown in the video (time-lapse) to get free, but this period may vary a lot. The actinula settles by its aboral end and elongates to form a juvenile polyp. It may settle on the perisarc of adults, as is seen in the video. Newly released actinulae have aboral tentacles and rudiments of oral tentacles.
References:
Imazu, M.A., Ale, E., Genzano, G.N. & Marques, A. C. 2014. A comparative study of populations of Ectopleura crocea and Ectopleura ralphi (Cnidaria, Hydrozoa, Tubulariidae) from the Southwestern Atlantic Ocean. Zootaxa 3753 (5): 421–439.
More images of hydroids and marine beings at http://cifonauta.cebimar.usp.br/
Support
CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico, Edital MCT/CNPq nº 42/2007 - Difusão e Popularização da C&T (processo nº 551951/2008-7).
Centro de Biologia Marinha, Universidade de São Paulo
http://cebimar.usp.br/index.php/pt/
https://www.facebook.com/cebimarusp
While humans age and die (which is kind of a bummer), it looks like hydras will stay young and fertile forever. Why is this? And what can we learn from these te...
While humans age and die (which is kind of a bummer), it looks like hydras will stay young and fertile forever. Why is this? And what can we learn from these tentacular microscopic organisms?
Hosted by: Hank Green
----------
Dooblydoo thanks go to the following Patreon supporters -- we couldn't make SciShow without them! Shout out to Justin Ove, Chris Peters, Philippe von Bergen, Fatima Iqbal, John Murrin, Linnea Boyev, Justin Lentz, and David Campos.
----------
Like SciShow? Want to help support us, and also get things to put on your walls, cover your torso and hold your liquids? Check out our awesome products over at DFTBA Records: http://dftba.com/scishow
Or help support us by becoming our patron on Patreon:
https://www.patreon.com/scishow
----------
Looking for SciShow elsewhere on the internet?
Facebook: http://www.facebook.com/scishow
Twitter: http://www.twitter.com/scishow
Tumblr: http://scishow.tumblr.com
Instagram: http://instagram.com/thescishow
REFERENCES
http://www.eurekalert.org/jrnls/pnas/pdfs/pnas.201521002.pdf
http://www.eurekalert.org/jrnls/pnas/si/pnas.201521002SI.pdf
http://www.britannica.com/animal/Hydra-hydrozoan-genus
http://www.els.net/WileyCDA/ElsArticle/refId-a0001096.html
http://www.sciencedaily.com/releases/2010/03/100314150922.htm
IMAGE/VIDEO SOURCES
https://commons.wikimedia.org/wiki/File:Hydravulgaris.jpg
https://commons.wikimedia.org/wiki/File:Lernaean_Hydra_Getty_Villa_83.AE.346.jpg
https://commons.wikimedia.org/wiki/File:Hydr1004.webm
While humans age and die (which is kind of a bummer), it looks like hydras will stay young and fertile forever. Why is this? And what can we learn from these tentacular microscopic organisms?
Hosted by: Hank Green
----------
Dooblydoo thanks go to the following Patreon supporters -- we couldn't make SciShow without them! Shout out to Justin Ove, Chris Peters, Philippe von Bergen, Fatima Iqbal, John Murrin, Linnea Boyev, Justin Lentz, and David Campos.
----------
Like SciShow? Want to help support us, and also get things to put on your walls, cover your torso and hold your liquids? Check out our awesome products over at DFTBA Records: http://dftba.com/scishow
Or help support us by becoming our patron on Patreon:
https://www.patreon.com/scishow
----------
Looking for SciShow elsewhere on the internet?
Facebook: http://www.facebook.com/scishow
Twitter: http://www.twitter.com/scishow
Tumblr: http://scishow.tumblr.com
Instagram: http://instagram.com/thescishow
REFERENCES
http://www.eurekalert.org/jrnls/pnas/pdfs/pnas.201521002.pdf
http://www.eurekalert.org/jrnls/pnas/si/pnas.201521002SI.pdf
http://www.britannica.com/animal/Hydra-hydrozoan-genus
http://www.els.net/WileyCDA/ElsArticle/refId-a0001096.html
http://www.sciencedaily.com/releases/2010/03/100314150922.htm
IMAGE/VIDEO SOURCES
https://commons.wikimedia.org/wiki/File:Hydravulgaris.jpg
https://commons.wikimedia.org/wiki/File:Lernaean_Hydra_Getty_Villa_83.AE.346.jpg
https://commons.wikimedia.org/wiki/File:Hydr1004.webm
KHANTECH Education has brought you lecture of Anum Ejaz on "Biology | Class Hydrozoa | Classification of Phylum Cnidaria".
#Biology #Phylum_Cnidaria #hydrozoa ...
KHANTECH Education has brought you lecture of Anum Ejaz on "Biology | Class Hydrozoa | Classification of Phylum Cnidaria".
#Biology #Phylum_Cnidaria #hydrozoa #classification #khantech_education
Phylum cnidaria is divided into three classes:
Anthozoa
Hydrozoa
Scyphozoa
CLASS HYDROZOA
Hydrozoans are small relatively common cnidarians. The vast majority are marine, but this is the one cnidarian class with freshwater representative.
HYDROZOA Cnidaria with polyp dominant.
One of the few fresh water cnidaria.
They are also found in attached to underwater plant or rocks, mostly in lakes and ponds.
Three features distinguish hydrozoans from other cnidarians:
Nematocyst are only in the epidermis.
Gametes are epidermal and are release at the outside of the body rather than into the gastrovascular cavity.
The mesoglea is largely acellular.
Follow us on Facebook:
https://www.facebook.com/Khantech-Education-101718234701186/
Like, Share and Don't Forget to Subscribe KHANTECH Education. Thanks
KHANTECH Education has brought you lecture of Anum Ejaz on "Biology | Class Hydrozoa | Classification of Phylum Cnidaria".
#Biology #Phylum_Cnidaria #hydrozoa #classification #khantech_education
Phylum cnidaria is divided into three classes:
Anthozoa
Hydrozoa
Scyphozoa
CLASS HYDROZOA
Hydrozoans are small relatively common cnidarians. The vast majority are marine, but this is the one cnidarian class with freshwater representative.
HYDROZOA Cnidaria with polyp dominant.
One of the few fresh water cnidaria.
They are also found in attached to underwater plant or rocks, mostly in lakes and ponds.
Three features distinguish hydrozoans from other cnidarians:
Nematocyst are only in the epidermis.
Gametes are epidermal and are release at the outside of the body rather than into the gastrovascular cavity.
The mesoglea is largely acellular.
Follow us on Facebook:
https://www.facebook.com/Khantech-Education-101718234701186/
Like, Share and Don't Forget to Subscribe KHANTECH Education. Thanks
Hydrozoan Life Cycle
Ectopleura crocea (Cnidaria, Hydrozoa, Hydroidolina, Anthoathecata, Aplanulata, Tubulariidae) is a common marine hydroid in the Atlantic ocean, usually abundant on artificial substrates. They form dense tufs with hundreds of individuals, which hydrocaulli are up to 10-12 cm long. The species doesn't have a medusa in its life cycle, and gametes are produced within structures called gonophores, which stay fixed to the polyp body. Individuals are either male or female. Spermatozoa are released into the water from male gonophores, fertilizing the eggs that remain within female gonophores. Embryos develop inside female gonophores into actinula larvae, the dispersive stage of the species. A mature female polyp releases hundreds of actinulae. As you may see in the video, the actinula larva struggles to get free from the gonophore. It pushes several times using its tentacles; it succeeds in liberating one tentacle at a time, until it finally got out through the aperture of the gonophore. It took about 2 hours for the actinula shown in the video (time-lapse) to get free, but this period may vary a lot. The actinula settles by its aboral end and elongates to form a juvenile polyp. It may settle on the perisarc of adults, as is seen in the video. Newly released actinulae have aboral tentacles and rudiments of oral tentacles.
References:
Imazu, M.A., Ale, E., Genzano, G.N. & Marques, A. C. 2014. A comparative study of populations of Ectopleura crocea and Ectopleura ralphi (Cnidaria, Hydrozoa, Tubulariidae) from the Southwestern Atlantic Ocean. Zootaxa 3753 (5): 421–439.
More images of hydroids and marine beings at http://cifonauta.cebimar.usp.br/
Support
CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico, Edital MCT/CNPq nº 42/2007 - Difusão e Popularização da C&T (processo nº 551951/2008-7).
Centro de Biologia Marinha, Universidade de São Paulo
http://cebimar.usp.br/index.php/pt/
https://www.facebook.com/cebimarusp
While humans age and die (which is kind of a bummer), it looks like hydras will stay young and fertile forever. Why is this? And what can we learn from these tentacular microscopic organisms?
Hosted by: Hank Green
----------
Dooblydoo thanks go to the following Patreon supporters -- we couldn't make SciShow without them! Shout out to Justin Ove, Chris Peters, Philippe von Bergen, Fatima Iqbal, John Murrin, Linnea Boyev, Justin Lentz, and David Campos.
----------
Like SciShow? Want to help support us, and also get things to put on your walls, cover your torso and hold your liquids? Check out our awesome products over at DFTBA Records: http://dftba.com/scishow
Or help support us by becoming our patron on Patreon:
https://www.patreon.com/scishow
----------
Looking for SciShow elsewhere on the internet?
Facebook: http://www.facebook.com/scishow
Twitter: http://www.twitter.com/scishow
Tumblr: http://scishow.tumblr.com
Instagram: http://instagram.com/thescishow
REFERENCES
http://www.eurekalert.org/jrnls/pnas/pdfs/pnas.201521002.pdf
http://www.eurekalert.org/jrnls/pnas/si/pnas.201521002SI.pdf
http://www.britannica.com/animal/Hydra-hydrozoan-genus
http://www.els.net/WileyCDA/ElsArticle/refId-a0001096.html
http://www.sciencedaily.com/releases/2010/03/100314150922.htm
IMAGE/VIDEO SOURCES
https://commons.wikimedia.org/wiki/File:Hydravulgaris.jpg
https://commons.wikimedia.org/wiki/File:Lernaean_Hydra_Getty_Villa_83.AE.346.jpg
https://commons.wikimedia.org/wiki/File:Hydr1004.webm
KHANTECH Education has brought you lecture of Anum Ejaz on "Biology | Class Hydrozoa | Classification of Phylum Cnidaria".
#Biology #Phylum_Cnidaria #hydrozoa #classification #khantech_education
Phylum cnidaria is divided into three classes:
Anthozoa
Hydrozoa
Scyphozoa
CLASS HYDROZOA
Hydrozoans are small relatively common cnidarians. The vast majority are marine, but this is the one cnidarian class with freshwater representative.
HYDROZOA Cnidaria with polyp dominant.
One of the few fresh water cnidaria.
They are also found in attached to underwater plant or rocks, mostly in lakes and ponds.
Three features distinguish hydrozoans from other cnidarians:
Nematocyst are only in the epidermis.
Gametes are epidermal and are release at the outside of the body rather than into the gastrovascular cavity.
The mesoglea is largely acellular.
Follow us on Facebook:
https://www.facebook.com/Khantech-Education-101718234701186/
Like, Share and Don't Forget to Subscribe KHANTECH Education. Thanks
Hydrozoa (hydrozoans, from ancient Greek ὕδρα, hydra, "sea serpent" and ζῷον, zoon, "animal") are a taxonomicclass of individually very small, predatory animals, some solitary and some colonial, most living in salt water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in fresh water. Hydrozoans are related to jellyfish and corals and belong to the phylumCnidaria.
Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. For example, Hydra has no medusoid stage, while Liriope lacks the hydroid stage.
Polyps
The hydroid form is usually colonial, with multiple polyps connected by tubelike hydrocauli. The hollow cavity in the middle of the polyp extends into the associated hydrocaulus, so that all the individuals of the colony are intimately connected. Where the hydrocaulus runs along the substrate, it form a horizontal root-like stolon that anchors the colony to the bottom.