Scyphozoan Life Cycle

1. Planula : The free-swimming medusa is either female or male and produces eggs or sperm which combine to produce a larva, called a planula. The planula is planktonic and will float around until it finds a substrate to bind to.

2. Scyphistoma : Once the planula binds to a substrate it develops into a scyphistoma. Scyphistoma is a feeding polyp with protruding tentacles on top used to catch food particles.

3. Strobila : The polyp soon turns into a reproductive polyp with stacks of strobilae. The strobilae are immature medusa that are being asexually reproduced by the polyp.

4. Ephyra : When a strobila is mature it breaks away from the reproductive polyp as a planktonic ephyra.

5. Medusa : The ephyra matures into a full grown medusa.


Field trip to Bodega Bay (1/26/14) Finale: My favorite pictures from the day

1) Bat Star and Pisaster right next to each other, with Pisaster’s tube feet visible. Pisaster was more prevalent where there more waves, since it mostly ate mussels, while the bat stars ate more algae, which grew with less waves, so it was cool to see them both right next to each other

2) Scyphozoan Jelly on the mudflats. The red spots are eyespots. We thought the fluffy tan things in the middle might be the oral arms retracted in for low tide. We also thought it (and all the others we found) were dead, but then we put them in a bucket and they were fine. (One thing I learned on this field trip was that cnidarians can in fact survive on the coast at low tides.)

Pacific Ocean Nettle by Bimo_SatriyoCW Chrysaora fuscescens (commonly known as the Pacific sea nettle or West Coast sea nettle) is a common free-floating scyphozoan that lives in the East Pacific Ocean from Canada to Mexico.

Sea nettles have a distinctive golden-brown bell with a reddish tint. The bell can grow to be larger than one meter (three feet) in diameter in the wild, though most are less than 50 cm across. The long, spiraling, white oral arms and the 24 undulating maroon tentacles may trail behind as far as 15 feet. For humans, its sting is often irritating, but rarely dangerous.(wikipedia)


Atolla wyvillei

An amazing short video (1:17) showing the bioluminescence of the deep-sea scyphozoan jellyfish, Atolla wyvillei (Coronatae - Atollidae), as seen from the Johnson-Sea-Link submersible with the lights on and then in the laboratory, after capture, with the lights off, exhibiting a burglar alarm display.

Is worth seeing!

(Video courtesy of Operation Deep Scope 2005 Exploration, Edith A. Widder, NOAA-OE)


Medusa Freshwater (Craspedacusta sowerbii) Freshwater Jellyfish

Craspedacusta sowerbii is a freshwater jellyfish in the phylum Cnidaria. Since it is classified as a hydrozoan, it is one of many jellyfish that are also known as hydromedusae. Hydromedusan jellyfish differ from scyphozoan jellyfish because they have a muscular, shelf-like structure called a velum on the ventral surface, attached to the bell margin. Originally from the Yangtze basin in China, C. sowerbii is an invasive species now found throughout the world in bodies of fresh water. wikipedia

Viktor Vrbovský photographer