These notes have been modified and significantly revised from a 2004 Special Species Symposium handout and subsequently the 2006 International Conference on Exotics Proceedings and the 2007 & 2008 AVMA Conventions.
Invertebrate animals comprise 95% of the animal kingdom's species, yet non-parasitic invertebrates are vastly underrepresented in the typical veterinary school curriculum. These notes and the accompanying lecture provide a brief introduction to some of the more prominent invertebrate groups (coelenterates, mollusks, crustaceans, echinoderms, insects, the horseshoe crab, and spiders) and review the state of the science with regards to clinical techniques. These notes are by no means comprehensive, and are primarily meant to inform the interested clinician on the clinical possibilities related to working with invertebrates.
The phylum Porifera is a diverse group of primitive animals commonly referred to as the sponges. Until the early 1800's sponges were actually classified as plants. Sponges occur in the fossil record back to the Precambrian (over 600 million years ago) and were the most important contributors to reefs during the Palaeozoic and Mesozoic Eras (Hooper and Van Soest, 2002). All members lack defined organs; differentiated cells within connective tissue perform necessary biological functions. A unique system of water canals facilitate transport of food, waste products, and gametes. Nearly all are sessile and most species are marine. Most of the 15,000 species are marine but about 3% of sponges live in freshwater environments. Sponges are normally found on firm substrates in shallow water, although some occur on soft bottoms.
1. Sponges maintain a close association with a variety of bacterial genera, some of which can be pathogenic.
2. Virtually nothing is known about analgesia, anesthesia, and therapeutics of sponges.
3. Sponges seem to tolerate surgical manipulation in the form of cutting and auto-grafting.
4. Sponges are an integral part of coral reef and other aquatic communities.
5. Natural products produced by sponges are important to biomedical science.
Hooper JNA and RWM Van Soest. 2002. Systema Porifera: A Guide to the Classification of sponges (Vols. 1 and 2). Kluwer Academic/Plenum Publishers, New York.
Kuhns WJ, Ho M, Burger MM, and R Smolowitz. 1997. Apoptosis and tissue regression in the marine sponge Microciona prolifera. Biol. Bull. 193:239-241.
Lewbart GL. 2006. Porifera. In: Invertebrate Medicine, Lewbart GA (ed.). Blackwell Publishing, Ames, IA, pp. 7-17.
Lauckner G. 1980. Diseases of Porifera. In: Diseases of Marine Animals (vol. 1), O. Kinne ed. John Wiley & Sons, pp. 139-165.
Rützler K (Ed.). 1990. New perspectives in Sponge Biology. Smithsonian Institution Press, Washington, DC, pp. 188.