A Sponge

Myxilla fimbriata

Bright orange sponge forming low, thick cushions or mounds on bedrock. Large holes (oscules), up to 10 millimetres in diameter, are sparsely scattered across its surface.

Authority

Bowerbank, 1864

Classification Details

Phylum: Porifera (sponges); Class: Demospongiae (siliceous sponges).

Habitat

Found on bedrock. Widespread in the North Atlantic, known from the Arctic to France. Locally it has been recorded from the Bay of Fundy and Gulf of Maine.

Diet

Sponges feed on small particles in the seawater. 80% of their diet is bacteria-sized particles (<0.5 micrometres in diameter). They suck seawater into a network of canals in their body using a current generated by cells called choanocytes. The choanocytes also capture the food particles.

Reproduction

Hermaphrodite – individuals are both male and female. Sperm is released into the water column, then sucked up by another sponge and used to fertilize its eggs. The sponge then broods the resulting embryos in its body tissue until they develop into free-swimming larvae that are released into the seawater. After a few days in the seawater, the larvae settle and develop into adult sponges.

Fun Facts

When scientists preserve this species in alcohol, it changes from yellow to a dark chocolate brown colour. Chemical reactions with air or preservatives result in significant colour changes in some sponge species. These can be a useful identification character.

References

Bowen S, Goodwin C, Kipling D, Picton B (2018) Sea squirts and sponges of Britain and Ireland. Plymouth: Wild Nature Press.

Goodwin C (2017) Field guide to the sponges of the Bay of Fundy. Huntsman Marine Science Centre. Available from https://www.researchgate.net/publication/319433507_Field_Guide_to_Sponges_of_the_Bay_of_Fundy

Van Soest RWM, Boury-Esnault N, Hooper JNA, Rützler K, de Voogd NJ, Alvarez B, Hajdu E, Pisera AB, Manconi R, Schönberg C, Klautau M, Kelly M, Vacelet J, Dohrmann M, Díaz M.-C, Cárdenas P, Carballo JL, Ríos P, Downey R and Morrow CC (2019) World Porifera Database. Myxilla (Myxilla) fimbriata (Bowerbank, 1866). Accessed at: http://www.marinespecies.org/porifera/porifera.php?p=taxdetails&id=169461 on 20 November 2020.

Van Soest R, Picton B, Morrow C (2000) Myxilla fimbriata – Sponges of the NE Atlantic. http://species-identification.org/species.php?species_group=sponges&id=340&menuentry=soorten Accessed online 20 November 2020.