Cylindrica Salp, Iasis cylindrica

Cylindrica Salp, Iasis cylindrica, Blastozooid or Aggregate Stage. Collected off the ocean surface with a small mesh bait net in the coastal waters of Cabo San Lucas, Baja California Sur, March 2018. Size: ca. 0.25 cm (0.1 inches) in diameter.  Chain length: ca. 30 cm (12 inches).

Cylindrica Salp, Iasis cylindrica, Oozooid or Solitary Stage. Collected off the ocean surface with a small mesh bait net in the coastal waters of Cabo San Lucas, Baja California Sur, March 2018. Size: ca. 5.1 cm (2.0 inches) x 1.3 cm (0.5 inches).

Cylindrica Salp, Iasis cylindrica, Blastozooid or Aggregate Stage. Photograph taken from a tidal pool in the greater Los Barilles area, Baja California Sur, February 2024. Size: ca. 0.25 cm (0.1 inches) in diameter.  Chain length: ca. 15 cm (5.9 inches). Photographs courtesy of Lisa Alex, Sandy, Oregon.

Cylindrica Salp, Iasis cylindrica, Oozooid or Solitary Stage. Photograph taken from a tidal pool in the greater Los Barilles area, Baja California Sur, February 2024.  Size: ca. 5.1 cm (2.0 inches) x 1.3 cm (0.5 inches). Photograph courtesy of Lisa Alex, Sandy, Oregon.

Phylogeny: The Cylindrica Salp, Iasis cylindrica (Cuvier, 1804), is a member of the Salipidae Family of Salps. The Iasis Genus of Salps is one of thirteen Genera in this Family, and this Genus has just one member, this species. In Mexico this species is known as sálpido cilíndrico.

Morphology:  Cylindrica Salps are transparent tubular gelatinous animals normally found co-existing in both stages of their complex life cycle, either in the blastozooid or aggregate stage which is comprised of long chains of tens to hundreds of small individual animals that can be up to 30 cm (12 inches) in length; or in the oozooid or solitary stage. In the aggregate phase they are oval in shape with short hollow projections anteriorly and posteriorly. They have soft, smooth “shells” that are fusiform, thick and voluminous. They have five body muscles. In this phase the individuals have a maximum body length of 0.3 cm (0.1 inches). In the solitary phase  Cylindrica Salps are elongated and cylindrical, with a rounded anterior end and a square cut posterior end. They are covered with a thin, soft, smooth “shell”. They have nine body muscles. Cylindrical Salps in this phase have a maximum body length of 20.7 cm (8.1 inches)

Habitat and Distribution:  Cylindrica Salps are pelagic can be found from the ocean’s surface to depths up to at least 688 m (2,250 feet), though some sources give them a maximum depth of 4,791 m (15,718 feet). The Cylindrica Salp is the most common species of Salpidae and is widely distributed being found in the tropical waters of the Atlantic, Indian and Pacific Ocean. In Mexican waters they are known to the Gulf of Mexico in the Atlantic and the Sea of Cortez in the Pacific Ocean.

Diet:  Cylindrica Salps feed on phytoplankton, which they filter from the water by use of a mucus net. They are vertical migrators that follow their food source to various depths within the water column generally moving up in the water column at night for feeding and retreating to the depths for protection during daylight hours. They can be found in large blooms that consist of tens of billions of individual animals. Both phases of Cylindrica Salps have  bodies that are in constant motion as they feed. In the aggregate phase they have been observed moving through the water in the form of a helix.

Predators:  Cylindrica Salps are eaten by sea turtles and fish, such as the Ocean Sunfish, Mola mola. They are also possibly eaten by crustaceans and sea birds. Salps in general are eaten by at least one hundred and forty-nine species of fish.

Reproduction:  Cylindrica Salps reproduce both sexually and asexually.

Ecosystem Interactions:  Cylindrica Salps are widespread and prolific and  they are an important component in the ocean foodweb. We are unaware of any research relating to commensal or other relationships.

Human Interactions:  Cylindrica Salps have a significant impact on commercial fisheries. Salps pose no significant threat to human activities. From a conservation perspective the Cylindrica Salp has not been evaluated however they have a wide global distribution and when present they can be found by the billions making them of Least Concern.

Synonyms: Salpa coerulescens, Salpa cylindrica, Salpa cymbiola, Salpa elongata, Salpa garnotii, Soestia cylindrica, and Weelia cylindrica.

Productive discussions and identifications courtesy of Linsey Sala, Scripps Institution of Oceanography, La Jolla, California.