2. General characters:
• Kingdom: Animalia
• Habitat: Aquatic, mostly marine,except one family, spongillidae few are terrestrial
• Habit: They are solitary or colonial.
• Grade of organization: cellular grade of body(multicellular)
• Shape: Body shape is variable, mostly cylinder shaped
• Symmetry: Asymmetrical or radially symmetrical.
• Germ layer: Diploblastic animals. The adult body wall contains two layers, outer dermal layer and inner gastral layer. In
between these two layers, there is a gelatinous and non-cellular mesoglea containing numerous free amoeboid cells.
• Coelom: Absent; acoelomate but spongocoel is present
• Surface of the body has numerous perforation called ostia (for the entry of water) and a large pore at the apex called
osculum (for the exit of water).
• Water canal system present
• Endoskeleton: Either calcareous spicules (calcium carbonate) or siliceous spicules (silica) or sponging fibers (protein).
• Mouth absent, excretory and respiratory organ absent.
• Nutrition: holozoic
• Digestion: Intracellular
• Nervous system: absent
• Circulatory system: absent
• Reproduction: Asexual: by budding or gemmule or regeneration; Sexual: gamatic fusion
• Fertilization: Internal
• Organisation of sponge have been grouped into 3 main type: ascon sycon and leuconoid type
3.
4. 1.Leucosolenia
• Phylum. Porifera Pore bearing, cellular grade, asymetrical or
radiallymmetrical.
• Class. Calcarea Calcareous spicules present. Syconoid sponges with
internal folds, exclusively marine
• Order: leucosolemia (homocoela) asconoid sponge with radial symmetrical
cylindral body,body wall thin and not folded.
Habit and habitat
Marine colonial sponge found in shallow waters.
Comments:
(1) Colony is composed of bunches of whitish vertical cylinders and tubes about 25 mm long.
(2) Vertical tubes of the colony contain osculum distally. They are joined together by horizontal
tubes at the base. The surface of the body is perforated by numerous pores or ostia or incurrent
pores.
(3) Magnified portion of the colony shows vase-shaped individuals, inhalent ostia, tri-radiate
spicules and horizontal branches attached to substratum.
5. (4) Simplest sponge with ostia spongocoel OSculum arrangement of water current. Canal
system simplest of ascon type. Osculum is surrounded by oscular fringe.
(5) Body wall is composed of dermal epithelium forming outer layer, and Choanocyte layer forming
inner layer, separated by middle mesenchyme layer.
(6) Calcareous spicules are monaxon or Triaxon.
(7)asexual repproduction by budding,branching,and regeneration, and sexual by gamte formation
6. •Classiflication :
•Phylum. Porifera Pore bearing cellular grade, asymmetrical or
radially symmetrical
•Class. Hexactinellida Glass sponges with siliceous spicules of triaxon or sixpointed
•Order. Hexasterophora: spicules are hexaster (star like shape)
•Habit and habitat: Euplectella is solitary animal found abundantly in deep waters.
•Comments:
•(1) Commonly called as Venus's flower basket due to its beautiful elegant
glossy shape.
•(2) Body is long, rigidly curved and cylindrical.
•(3) Body is composed of four and six-rayed siliceous spicules, interlaced and
fused at their tips forming three dimensional net-work with parietal gaps.
• (4) It is attached to the substratum by long siliceous threads of root tuft.
•(5) its upper end is closed by an oscular sieve plate.
•They are in great demand in japan for marriage ceremonys because of its
skeletons with commensel crustacean are costly wedding present as a symbol of “
union till death” .
2. Eupectella
7. Phylum.. Porifera : Pore bearing cellular grade, asymmetrical or radially symmetncal.
Class : hexactinellida :Glass sponges with siliceous spicales of triaxon or six-pointed t
Order : amphidiscophora : spicules are amphidiscus. No hexaster.
Habit and habitat: Hyalonema is marine animal, found 60 to 95 fathoms deep
Distribution : Found along new England coast.
Comments:
(1) Commonly called as glassrope sponge.
(2) Body is spherical or ovoidal and axially traversed by a bundle
of long spicules.
(3) Spicules are often fused to form a lattice(net)-like skeleton, giving
the sponge a glasslike appearance when dried.
Hyalonema
8. 4) Glass sponges are most symmetrical and most individualized. Body is cup or vase-shaped
measuring 10 to 30 cm in height. Spongocoel is well developed. Osculum contains sieve plate.
(5) Stick or columella is composed of a root tuft or root spicules which acts as hold fast organ.
(6)Root spicules are compact, stalk like elongated, twisted and giving ne appearance of a rope.
The middle columella contain symbiotic polyps (Epizoanthus).
(7)it prosses large and small amphidisk spicules like fresh-water sponges. Entire body contains
small, branching, six-rayed spicules resembling Christmas trees on cross-shaped bases.
(8)flagellated chambers are arranged radially and in parallel planes in the sponge
