Environment : Sponges

Algae, Sponges, Hydrozoans on "Vicissitudes Girl"

Algae, Sponges, Hydrozoans on “Vicissitudes Girl

Algae, Sponges, Hydrozoans on "Vicissitudes Girl"

Algae and Sponges on “Vicissitudes Boy

Brown encrusting sponge on chin on "Tam CC Project"

Brown encrusting sponge on chin on “Tam CC Project

SPONGES (Porifera)

Sponges are sessile bottom dwelling filter feeding animals. They attach to a solid substrate and are one of the simplest multi-cellular animals in the marine environment. Their bodies consist of a gelatinous layer (mesophyl) with a thin layer of cells either side. The mesophyl acts as an endoskeleton and encrusts onto rock surfaces. The scientific name for them is Porifera meaning “pore bearing” or Ostia. The network of Ostia channel into an internal system of canals and converge into one or more larger holes called the Oscula. The channels function to move water through the sponge using specialised cells with whip-like fronds to bring Oxygen and nutrients in while filtering food particles and removing waste products via diffusion. Most sponges are hermaphroditic and do not have distinct nervous, digestive or circulatory systems.

Sponges are Encrusting (typically over rock surface) or Free-standing (eg Barrel Sponges can grow to over 6 feet) and the typical shape is that of a vase, however there growth patterns vary hugely. They range in a variety of colours and may live for over 200 years in tropical waters and exceed depth of 8000 metres. Demosponges consist of 90% of sponge species. They use demospongin to strengthen the mesophyl layer. Calcareous sponges with calcium carbonate spicules or even an exoskeleton are only found in shallow waters.

Symbioses: Some species have evolved symbiotic relationships. Photosynthesising microorganisms (often green algae or cyanobacteria)can live on and in sponges forming a mutualistic relationship. Crabs , lobsters, starfishes, reef fishes, worms, crinoids, sea cucumbers live on and attach for camouflage and for a food source, while sponges in turn grow upon and through other organisms. Most species of sponges feed on bacteria and food particles in the water a few have evolved to be carnivorous.

“Snorkelling Guide to Marine Life” by Paul Humann, Ned DeLoach




Demospongiae sp. on "Vicissitudes Boy"

Demospongiae sp. on "Vicissitudes Boy"

Demospongiae sp. on “Vicissitudes Boy

Green coloured sponge: Demospongiae sp. on "Vicissitudes Boy"

Green coloured sponge: Demospongiae sp. on "Vicissitudes Boy"

Green coloured sponge: Demospongiae sp. on “Vicissitudes Boy


Kingdom: Anamalia

Phylum: Porifera

Class: Demospongiae

These are the largest class of Sponges, including over 90% of species and are abundant and diverse in shallow non-polar waters. Their skeletons consist of the protein Spongin or the mineral Silica (or both) forming “spicules”. The majority are Lueconoid in structure which are the most complex of anatomy of the sponges. They consist of more than 2 million chambers and over 80,000 intake canals to increase the efficiency at which absorption of nutrients takes place. Demospongae come in a variety of colours and body shapes. They asexually reproduce via budding or the productions of gemmules.

Both of these photographs are thought to be of the family Dictyodendrillidae, and an Igernella sp. They are of two sculptures making up “Vicissitudes” in Grenada, West Indies taken 4 years after installation. The 26 sculptures in the ring also have large tubular projections of the sponge extending towards the sea surface from the structure.

“Snorkelling Guide to Marine Life” by Paul Humann, Ned DeLoach



Callyspongia vaginalis on "Vicissitudes Boy"

Callyspongia vaginalis on “Vicissitudes Boy

Family: Callyspongia, thought to be Species: Leuconia palaoensis on "Vicissitudes Girl"

Family: Callyspongia, thought to be Species: Leuconia palaoensis on “Vicissitudes Girl

Agelas conifera on "Vicissitudes Boy"

Agelas conifera on “Vicissitudes Boy




Family: Callyspongia

One of the most common colonies of demospongae found on the reef and distinguished by its long tubular growths or an overall vase shape. The projections resemble antlers protruding in shallows but they are found living at varying depths. Filtered water is ejected through the large openings on the ends of the antlers They range in color from pinks to purple to blue, gray, and gray-green. This is one of the few reef invertebrates that can be blue in color.

The Photographs of the tubular sponges and the pink branching sponge are thought to be of the family Callyspongia, found only reef’s and are very common in the Caribbean. They have grown very rapidly and distorted the face of most of the sculpture in the ring of “Vicissitudes“.

“Snorkelling Guide to Marine Life” by Paul Humann, Ned DeLoach




Hydrozoans on "Vicissitudes Boy"

Hydrozoans on "Vicissitudes Boy"

Hydrozoans on “Vicissitudes Boy


Phylum: Cnidaria

Class: Hydrozoa

Order: Hydroida

Related to coral and Jelly Fish. They are small predatory colonial animals that are often confused as plants and grow on benthic strata (rocks and pilings). Each individual hydroid animal are zooids composed of stem pedicles and a flower-like head containing a mouth and tentacles, with multiple polyps connected together by tubular forms called hydrocauli making individuals of the colony interconnected. The polyps are designed for feeding and initial digestion within its central cavity. Some polyps within a colony are designated to reproduction. The hydrocaulus anchors the colony to the substrate like a root and distributes left over nutrition to the rest of the colony. The colonies are generally small and present a fan-like appearance. Many obtain their nutrition from endosymbiotic algae and dissolved particles from the reef and parasites. In return they provide CO2 to algae and plants. Hydra as pictured on Vicissitudes are different to the rest of the phylum and they miss out the Medusoid stage of the lifecycle therefore remaining as polyps for their entirety.

Fire Coral is not technically a coral but a colony of hydroids.

“Snorkelling Guide to Marine Life” by Paul Humann, Ned DeLoach