![]() Unless otherwise indicated, the written and visual content on this page is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Sponge grade body fossil with cellular resolution dating 60 Myr before the Cambrian. editors: Advances in Marine Biology: 61, The Netherlands: Amsterdam, Academic Press, pp. In Becerro, M.A., Uriz, M.J., Maldonado, M. Deep Phylogeny and Evolution of Sponges (Phylum Porifera). North American Paleontological Convention, Chicago. Sponges and reef and related facies through time. Journal of biotechnology, 70 1-3, 15-25. The discovery and development of marine compounds with pharmaceutical potential. Munro, M.H., Blunt, J.W., Dumdei, E.J., Hickford, S.J., Lill, R.E., Li, S., Battershill, C.N., & Duckworth, A.R. editors: Ecology and General Biology (Fourth Edition): Elsevier: Amsterdam, pp. Deep-sea sponge grounds: Reservoirs of biodiversity. Applied and Environmental Microbiology 68: 4431-4440. Molecular evidence for a uniform microbial community in sponges from different oceans. Study on the Habits of the Crab Dromia vulgaris M.E. The Ediacaran-Cambrian rise of siliceous sponges and development of modern oceanic ecosystems. Early sponge evolution: A review and phylogenetic framework. Current Opinion in Genetics & Development: 39, pp. Sponges as models to study emergence of complex animals. Some examples of these are shown below.Īdamska, M. Since it has two distinct points (growth directions), it would also be called diactine. Each pointed end of a spicule signifies a single growth direction, which differntiates between monoactine, diactine, triactine, hexactine, tetracline, and polyactine.įor example, a toothpick-shaped spicule has only one line (axis) so it would be monoaxon. Spicules can also be described in terms of the number of directions in which they grow. The number of crossing lines in a spicule determines how many axes it will have. If you think of a plus sign (+), it has two axes one horizontal and one vertical. The number of axes in a spicule differentiates between being called a monoaxon (one axis), triaxon (three axes), tetraxon (four axes), or polyaxon(many axes). Megascleres are large, whereas microscleres are small. Spicules are classified based on their structural characteristics and size. To be classified as a sponge, an organism must have spicules, which are needle-like secretions of calcium carbonate or silica. Mesohyl: cell layer between the choanocytes and external/internal body wall of sponge, this is where skeletal elements are produced and gametes are stored by many sponge cell types.Spongocytes: cells that secrete spongin.Sclerocytes: cells that secrete spicules.Pinacocytes: cells that create an outer covering of the sponge, like ‘skin’.Choanocytes: or ‘collar cells’ are flagellated cells in the body wall, which create currents to capture food particles.Archaeocytes: amoeboid cells that ingest/digest food particles and transport nutrients to other cells.Check out the video below to see different sponge cells in action! Sponges have several kinds of specialized cells that carry out specific life tasks. They essentially act as stem cells and switch to different forms when needed. Most cells in a sponge are totipotent, meaning they can move around and change function throughout their lifetime. Sponges also have several microscopic features that are more difficult to see with the naked eye. In this chapter we will explore the diversity and fossil record of phylum Porifera. They have a global distribution, occupy shallow to deep water conditions, and occur in virtually all marine and freshwater environments. Sponges encompass a vast diversity of asymmetrical shapes, sizes, and even hardnesses (ranging from soft and flexible to rock-hard). The beating flagella of the choanocytes create water currents that flow through the canals and pores in the sponge, bringing in oxygen and particles of food that are consumed. ![]() The cells lining the inside of the sponge are called choanocytes(‘collar cells’), which have a ‘tail-like’ flagellum. Spongin is the flexible material that makes up the body wall of the sponge, while spicules are hard, spiny secretions that help to provide a reinforced structure. Having no digestive tract, localized sensory region, or true tissues, they are little more than a cluster of cells supported by a structure of sponginand spicules. Sponges make up the simplest animal group on the planet: phylum Porifera (from the Latin porus ‘pore’ and ferre ‘to bear’).
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