Nereocystis (Greek for "mermaid's bladder") is a monotypic genus of kelp containing the species Nereocystis luetkeana. Some common names include edible kelp, bull kelp, bullwhip kelp, ribbon kelp, giant kelp, bladder wrack, and variations on these names. It forms thick beds on rocks, and is an important part of kelp forests. It can grow to a maximum of 36 m (118 ft).Nereocystis has a holdfast of about 40 cm (16 in), and a single stipe, topped with a pneumatocyst containing carbon monoxide, from which sprout the numerous (about 30-64) blades. The blades may be up to 4 m (13 ft) long, and up to 15 cm (5.9 in) wide. It is usually annual, sometimes persisting up to 18 months. Nereocystis is the only kelp which will drop spore patches, so that the right concentration of spores lands near the parent's holdfast. It is common along the Pacific Coast of North America, from Southern California to the Aleutian Islands, Alaska.
The thallus of this common canopy-forming kelp has a richly branched holdfast (haptera) and a cylindrical stipe 10–36 m (33–118 ft) long, terminating in a single, gas-filled pneumatocyst from which the many blades, up to 10 m (33 ft) long, develop. Blade growth can reach 15 cm (6 in) per day. Reproductive patches (sori) develop on the blades and drop to the seafloor at maturity.
This annual kelp grows on rock from the low intertidal to subtidal zones; it prefers semi-exposed habitats or high-current areas. Offshore beds can persist for one to many years, usually in deeper water than Eualaria or Macrocystis, where they co-occur.
^Fisher, K; Martone, P.T. (April 2014). "Field Study of Growth and Calcification Rates of Three Species of Articulated Coralline Algae in British Columbia, Canada". BIOLOGICAL BULLETIN. 226 (2): 121–130. PMID24797094.
Fisher, K; Martone, P.T. (April 2014). "Field Study of Growth and Calcification Rates of Three Species of Articulated Coralline Algae in British Columbia, Canada". BIOLOGICAL BULLETIN. 226 (2): 121–130. PMID24797094.
Poulson, Mary E.; McNeil, Andrew J.; Donahue, Raymon A. (Jul 2011). "Photosynthetic response of Nereocystis luetkeana (Phaeophyta) to high lightpre_614". Psychological Research. 59 (3): 156–165. doi:10.1111/j.1440-1835.2011.00614.x.
Britton-Simmons, Kevin; Eckman, James; Duggins, David (26 February 2008). "Effect of tidal currents and tidal stage on estimates of bed size in the kelp Nereocystis luetkeana". Marine Ecology Progress Series. 355: 95–105. doi:10.3354/meps07209.