NatureVolve

Rare salp dis­cov­ered in Nor­way - Heli­cos­alpa vir­gula

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Heli­cos­alpa is a genus of rare salps, and spec­i­mens can be­come over 15 me­ters long. They are typ­i­cally recorded in south­ern lat­i­tudes, but re­cently a few spec­i­mens were recorded to the north of Nor­way.

Only three Heli­cos­alpa species have been de­scribed in the world, and with a lit­tle help from ma­rine cit­i­zen sci­en­tists, we are hop­ing to gain tis­sue sam­ples for ge­netic anal­y­sis. Help us to find sam­ples from all three species!

Yes, you read it right! Salps are free-swim­ming tu­ni­cates, of which Heli­cos­alpa is one genus. They have a fas­ci­nat­ing life­cy­cle. You may en­counter heli­cos­alps ei­ther as soli­tary spec­i­mens, a few cen­time­ters long, or gi­ant chains which may be­come over 15 me­ters. The long chains look a bit like a ‘gi­ant he­lix’, and are able to swim by twist­ing their chains.

Heli­cos­alps be­gin their life­cy­cle as soli­tary salps, and through ‘bud­ding’ (asex­ual re­pro­duc­tion) they pro­duce a small, long chain with lots of in­di­vids. When long enough, this small chain breaks off from the sin­gle salp, and floats away. The small chain is grow­ing by fil­trat­ing and eat­ing par­ti­cles from the wa­ter mass. When the chain has grown large enough, and meets an­other chain, they ex­change egg and sperm and pro­duce sin­gle salps (sex­ual re­pro­duc­tion).

Salps are tu­ni­cates, and be­long within Chor­data phy­lum, to­gether with hu­mans, for ex­am­ple. All chor­dates have a dor­sal nerve cord, at least parts of their lives. Heli­cos­alps are among the most rare salps. They have been recorded both from the At­lantic and Pa­cific Ocean, but are typ­i­cally seen in the trop­ics, or in the Mediter­ranean Sea.

“Heli­cos­alps are among the most rare salps. They have been recorded both from the At­lantic and Pa­cific Ocean, but are typ­i­cally seen in the trop­ics, or in the Mediter­ranean Sea.”

Only three species have been de­scribed: Heli­cos­alpa vir­gula, H. ko­maii and H. younti. In the At­lantic, only H. vir­gula has been recorded. Heli­cos­alpa are so rare that even sci­en­tists have seen very few live spec­i­mens, and sci­en­tific de­scrip­tions of species have been based on pre­served spec­i­mens.

If you have worked with pre­served an­i­mals, you’ve no­ticed they look a lot dif­fer­ent from live an­i­mals: they’ve shrunk, lost color and are some­what de­formed. Be­cause of this, noone knew for sure what these three Heli­cos­alpa species looked like alive – un­til now:

Through our re­search study (Ringvold et al.*) we con­ducted google searches look­ing for pic­tures and videos of heli­cos­alps from divers all around the world.

A few pho­tos were also bor­rowed from other re­searchers.

Grad­u­ally, it be­came clear to us what the three spec­i­mens looked like alive!

H. vir­gula can be seen in Fig­ure 1 (pre­vi­ous page). No­tice the yel­low, cone-shaped go­nads with long pro­tru­sions; these are char­ac­ter­is­tic for H. vir­gula. In our next project, we wish to sam­ple a small piece of each Heli­cos­alpa species (a tis­sue sam­ple) in or­der to con­duct ge­netic anal­y­sis.

*Ringvold et al. 2020 - En­coun­ters with the rare genus Heli­cos­alpa (Chor­data, Thali­acea, Salp­ida), us­ing cit­i­zen sci­ence data. Ma­rine Bi­ol­ogy Re­search. 16 (5) 369-379.

 ?? © Nils Aukan. All rights re­served. ?? Right:
Fig­ure 1 - Heli­cos­alpa vir­gula, ob­served in Nor­way, Kris­tian­sund. Also ref­er­enced as fig­ure 3 from the team’s re­search pa­per pub­lished in Ma­rine Bi­ol­ogy Re­search of Ta­ly­lor & Fran­cis - Ringvold et al, 2020.
Link to re­search pa­per and image source.
© Nils Aukan. All rights re­served. Right: Fig­ure 1 - Heli­cos­alpa vir­gula, ob­served in Nor­way, Kris­tian­sund. Also ref­er­enced as fig­ure 3 from the team’s re­search pa­per pub­lished in Ma­rine Bi­ol­ogy Re­search of Ta­ly­lor & Fran­cis - Ringvold et al, 2020. Link to re­search pa­per and image source.
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