Porifera
Classification- Sponges "pore bearer". They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like meshohyl sandwiched between two thin layers of cells.Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes.
Traditionally, sponges have been regarded as a monophyletic group defined by several synapomorphies including the presence of:
Sponges are an exclusively aquatic and, with a few exceptions, a filter-feeding group of animals. The group consists of approximately 15,000 extant species in three distinct groups:
Diversity- Sponge bodies are diverse in form, ranging from encrusting sheets, to volcano-shaped mounds, to tubes as small as one millimeter or as large as one meter, and to upright sheets reminiscent of elephant ears. In all cases, poriferans have a canal system, through which they pump water. Water enters through pores called ostia, flows through canals to a spacious chamber called a spongocoel, and finally exits through large openings called oscula.Often, sponges are distinguished by the level of complexity exhibited by their bodies. The simplest form consists of a single tube two cell layers thick. Poriferans with this type of architecture are necessarily very small due to surface area to volume constraints. In order for a sponge to attain greater size, the sponge wall must be folded in on itself. A simple folding of the wall yields a sponge body with sycon organization. The vast majority of sponges are organized in a more complex way, the leucon condition, with folds upon folds, resulting in a series of flagellated chambers connected by canals. Ascon, sycon, and leucon are levels of complexity that grade one into the other.
Life History- In early branching event in the history of animals separated the sponges from other metazoans. As one would expect based on their phylogenetic position, fossil sponges are among the oldest known animal fossils, dating from the Late Precambrain. Since then, sponges have been conspicuous members of many fossil communities; the number of described fossil genera exceeds 900. The approximately 5,000 living sponge species are classified in the phylum Porifera, which is composed of three distinct groups, the Hexactinellida (glass sponges), the Demospongia, and the Calcarea (calcareous sponge).
Ecological Roles- Sponges reproduce by both asexual and sexual means. Most poriferans that reproduce by sexual means are hermaphroditic and produce eggs and sperm at different times. Sperm are frequently "broadcast" into the water column. That is, sperm are created, concentrated and sent out the excurrent openings, sometimes in masses so dense that the sponges appear to be smoking. These sperm are subsequently captured by female sponges of the same species. Inside the female, the sperm are transported to eggs by special cells called archaeocytes. Fertilization occurs in the mesenchyme and the zygotes develop into ciliated larvae. Some sponges release their larvae, where others retain them for some time. Once the larvae are in the water column they settle and develop into juvenile sponges. Sponges that reproduce asexually produce buds or, more often, gemmules, which are packets of several cells of various types inside a protective covering. Fresh water sponges of the Spongillidae often produce gemmules prior to winter. These then develop into adult sponges beginning the following spring.
Human Impacts- bath sponges have been used since bronze age; 4000 yrs holds up to 35 x’s its weight in water takes 5 yrs to reach marketable size. before 1940’s the Florida sponge fleet in Key West had >350 ships and employed 1400 people the sponge harvest ceased in 1940’s due to over collecting, red tides and a fungal disease that wiped out the sponge beds this was also the same time that synthetic sponges were introduced to the market sponges produce a wide variety of bio-active compounds: pharmaceuticals: antibiotics, asthma, arthritis, anticancer drugs, chemicals that promote wound healing, anti-inflammatories antibiotics against bacteria such as E. coli and Staph aureus. Acyclovir from Caribbean sponge 1st antiviral compound approved for human use fights herpes infections used since 1982 eg. Vidabarine Animals may attack AIDS virus a species of S Pacific sponge produces chemicals that can kill Candida a human pathogen that causes thrush and vaginal infections a new (2009) chemical derived from a sponge has the ability to resensitize bacterial pathogens to antibiotics they lose their resistance to all antibiotics and die.
Classification- Sponges "pore bearer". They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like meshohyl sandwiched between two thin layers of cells.Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes.
Traditionally, sponges have been regarded as a monophyletic group defined by several synapomorphies including the presence of:
- choanocytes
- an aquiferous system with external pores
- mineral spicules
- high cellular mobility and totipotency
Sponges are an exclusively aquatic and, with a few exceptions, a filter-feeding group of animals. The group consists of approximately 15,000 extant species in three distinct groups:
- the glass sponges (Class Hexactinellida)
- the calcareous sponges (Class Calcarea)
- the demosponges (Class Demospongiae)
Diversity- Sponge bodies are diverse in form, ranging from encrusting sheets, to volcano-shaped mounds, to tubes as small as one millimeter or as large as one meter, and to upright sheets reminiscent of elephant ears. In all cases, poriferans have a canal system, through which they pump water. Water enters through pores called ostia, flows through canals to a spacious chamber called a spongocoel, and finally exits through large openings called oscula.Often, sponges are distinguished by the level of complexity exhibited by their bodies. The simplest form consists of a single tube two cell layers thick. Poriferans with this type of architecture are necessarily very small due to surface area to volume constraints. In order for a sponge to attain greater size, the sponge wall must be folded in on itself. A simple folding of the wall yields a sponge body with sycon organization. The vast majority of sponges are organized in a more complex way, the leucon condition, with folds upon folds, resulting in a series of flagellated chambers connected by canals. Ascon, sycon, and leucon are levels of complexity that grade one into the other.
Life History- In early branching event in the history of animals separated the sponges from other metazoans. As one would expect based on their phylogenetic position, fossil sponges are among the oldest known animal fossils, dating from the Late Precambrain. Since then, sponges have been conspicuous members of many fossil communities; the number of described fossil genera exceeds 900. The approximately 5,000 living sponge species are classified in the phylum Porifera, which is composed of three distinct groups, the Hexactinellida (glass sponges), the Demospongia, and the Calcarea (calcareous sponge).
Ecological Roles- Sponges reproduce by both asexual and sexual means. Most poriferans that reproduce by sexual means are hermaphroditic and produce eggs and sperm at different times. Sperm are frequently "broadcast" into the water column. That is, sperm are created, concentrated and sent out the excurrent openings, sometimes in masses so dense that the sponges appear to be smoking. These sperm are subsequently captured by female sponges of the same species. Inside the female, the sperm are transported to eggs by special cells called archaeocytes. Fertilization occurs in the mesenchyme and the zygotes develop into ciliated larvae. Some sponges release their larvae, where others retain them for some time. Once the larvae are in the water column they settle and develop into juvenile sponges. Sponges that reproduce asexually produce buds or, more often, gemmules, which are packets of several cells of various types inside a protective covering. Fresh water sponges of the Spongillidae often produce gemmules prior to winter. These then develop into adult sponges beginning the following spring.
Human Impacts- bath sponges have been used since bronze age; 4000 yrs holds up to 35 x’s its weight in water takes 5 yrs to reach marketable size. before 1940’s the Florida sponge fleet in Key West had >350 ships and employed 1400 people the sponge harvest ceased in 1940’s due to over collecting, red tides and a fungal disease that wiped out the sponge beds this was also the same time that synthetic sponges were introduced to the market sponges produce a wide variety of bio-active compounds: pharmaceuticals: antibiotics, asthma, arthritis, anticancer drugs, chemicals that promote wound healing, anti-inflammatories antibiotics against bacteria such as E. coli and Staph aureus. Acyclovir from Caribbean sponge 1st antiviral compound approved for human use fights herpes infections used since 1982 eg. Vidabarine Animals may attack AIDS virus a species of S Pacific sponge produces chemicals that can kill Candida a human pathogen that causes thrush and vaginal infections a new (2009) chemical derived from a sponge has the ability to resensitize bacterial pathogens to antibiotics they lose their resistance to all antibiotics and die.