CONSEIL INTERNATIONAL POUR L'EXPLORATION DE LA MER
Zooplankton THALIACEA - I Sheet 9 Family: Salpidae (By J. H. Fraser) 1947.
https://doi.org/10.17895/ices.pub.4918 ISBN 978-87-7482-759-7 ISSN 2707-675X -2-
SOLITARY FORMS
Cyclosalpa bakeri Salpa /usi/ormis Salpa maxima Thalia democratica
=-
Iasis zonaria Ihlea asymmetrica Pegea con/oederata Thetys vagina (side view)
AGGREGATE FORMS
Cyclosalpa bakeri Salpa /usi/ormis Salpa maxima Thalia democratica (side view)
dorsal ventral
Iasis zonaria lhlea asymmetrica Pegea con/oederata Thetys vagina (side view)
Salps have an alternation of generations in their life history. Solitary forms ( =oozoids) are asexual and produce chains of aggregate sexual forms ( = blastozoids= gonozoids) by means of budding from a stolon. Asymmetrical aggregate forms are either dextral or sinistral according to the side of the stolon on which they developed. -3-
A. Intestinal tract not forming a haU:-shaped "nucleus" ...... Genus CYCLOSALPA B. Intestinal tract.forming a more or less compact "nucleus" ...... Genus SALPA (including the following sub-genera = Brooksia, Iasis, Ihlea, Metcalfina, Pegea, Ritteriella, Thalia, Thetys, Traustedtia ). The most satisfactory characters for specific identification are the number and arrangements of the muscle bands, which are characteristic from the early stages (> 3 mm.); and the shape of the test: - see figures.
Solitary Forms Aggregate Forms
Species Lcngrh in Other points (for dorsal Length in Other points (for dorsal u1m. Venlrnl m1n. Ventral Test muscles and shape of test Test Muscles muscles and shape of lest Normal/ Muscles Normal/ see figures) Max. see figures) Max.
1. Cyclosalpa bakeri 25/50 flaccid present Intestine parallel to gill. 30/50 very see figure Large intestinal loop in Ritter ...... Ring of granular Iumin- flaccid ".Post abdomen". Ante- ous material in lateral nor muscles continue in- edges. to vestigeal peduncle. Testis and caecum form trailing appendages. 2. Salpa fusiformis 40/80 rigid inter- Nucleus with reddish 30/80 rigid inter- Fusiform character (as Cuvier ...... rupted streaks rupted figure) usual, but p~o- tuberance 111ay occas10- nally be short. 2a. - var. aspera Test rigid and spinose Test rigid and spinose. Chamisso ...... Protuberances may be long or short. 3. Salpa maxima 50/160 rigid absent All muscles independent 50/150 rigid inter- - Forskal ...... rupted
4. Thalia democratica 25/ rigid continu- Test protrudes posterior- 15/ rigid ~idely - (Forskal) ...... OU~ ly in two large and sev- mter- era! smaller appendages rupted 5. Iasis zonaria 30/65 very inter- - 35/50 very ~idely Larger specimens ofte n (Pallas) ...... rigid rupted rigid inter- carry embryos up t 0 rupted 20 mm. lung. 6. lhlea asymmetrica 15/30 very present Usually found in a dis- 15/25 very asym- Some variability in pre (Fowler) ...... flaccid integrating condition. flaccid metrical cise details of muscl e (see figure) arranp;ements. Usuall y found in a disintegratin g condition. 7. Pegea confoederata 40/120 rigid absent Muscles do not reach to ? rigid absent Muscles barely reach th e (Forskal) ...... lateral edges of body near lateral edges of body. the nucleus 8. Thetys ragina < 190 rigid absent Number of body muscles < 190 rigid absent - (Tilesius) ...... (220 with varies. Dody produced append- posteriorly into two long ages) appendages. -4
F u r t h e r I n f o r m a t i o n o n I d e n t i f i c a t i o n. Distribution Species Figure• in brackets l. Cyclosalpa bakeri: Met ca 1f, 1918, p. 37, Plates 7-10. reft:r to species that 2. Salpa fusiformis: Metcalf, 1918, p.88, Figs.73,.77, 78; Ihle, 1927, p.26, only occur Figs.4, 5; Apstein, 1901, p.7, Fig.6. exceptionally. 2a. - form aspera: Met ca If, 1918, p. 92, Fig. 81; I h I e, 1927, p. 28. Gulf of Bothnia 3. Salpa maxima: Metcalf, 1918, p.83, Figs. 64, 67, 68; Ihle, 1927, p.26; Gulf of Finland A p stein, 1901, p. 10, Fig. 9. Baltic proper 4. Thalia democratica: Met ca If, 1918, p. 109, Figs. 104, 107; I h I e, 1927, p. 29, . Belt Sea Figs. 6, 7; A p stein, 1901, p. 6, Fig. 5 (as S. mucronata). Kattegat 5. Iasis zonaria: Metcalf, 1918, p.100, Figs.90, 97, 98; Ihle, 1927, p.28; Skagerak (4) A p stein, 1901, p. JO, Fig. 9. Northern North Sea 2, 4, 6 6. Ihlea asymmetrica: Met ca If, 1918, p. 183, Figs. 140, 145 (as Apsteinia); Southern North Sea I h I e, 1927, p. 25, Figs. 2, 3; A p stein, 1901, p. 8, Fig. 7. English Channel (eastern) (4) 7. Pegea con/oederata: Met ca If, 1918, p. 127, Figs. 119, 123; Ihle, 1927, p. 30. English Channel ( western) 2, 4, (5), (7), (8, 8. Thetys vagina: Met ca If, 1918, 121, Figs. 114, 117; I h I e, 1927, p. 30; A p Bristol Channel and Irish Sea s t e i n, 1901, p. 10, Fig. 11 (as Sal pa Tilesii). South and West Ireland and 1, 2, 2a, 3, 4, 5, 6, Atlantic (7), (8) (The following species are found in the North Atlantic and the Mediterranean Faroe Shetland Area 1, 2, 4, 5, 6 but have not yet been recorded from the area under consideration: Faroe Iceland Area (2), (5), (6) Cyclosalpa a/finis (Chamisso), Cyclosalpa pinnata (Forskal), C. pinnata Norwegian Sea 2, 4 var. polae (Sig I), Cyclosalpa virgula (Vogt), Brooksia rostrata (Tr au st e d t), Barents Sea lhlea punctata (Fors k a I), Salpa cylindrica (Cuvier), Metcalfina hexagona (Q. and G.), Ritteriella amboinensis (A p stein).) References to Work on Bio Io g y. Farran (1906), 2, 4, 6, 7; Fraser (194·) 1, 2, Salps normally occur at or near the surface of the warmer oceans but tend to 4, 5, 6; Garstang (1928), Morphology and Phy become mesoplanktonic as they are carried towards the north European coasts logeny; Harant et Vernieres (1938), Key; with a concomitant drop in temperature. They are found only in areas directly I h I e (1927), 2, 3, 4, 5, 6, 7, 8, Key; I h I e (1935), affected by oceanic water and are reliable "indicators" of such. The occurrence Anatomy, Life History, etc.; Met ca If (1918), 1, 2, of any particular species tends to be spasmodic and the distribution in the north 3, 4, 5, 6, 7, 8, Key; Russell and Hastings European area varies with the changes of the Atlantic influx. In favourable con (1933), 2, 4, 5; Streiff (1908), Musculature; ditions they may occur in large swarms. Thompson (1942), l, 2, 3, 4, 5, 6, 7, 8.
References. A p st e i n, C. 1894. Ergebn. Plankt. Exp. Humboldt-Stif I h I e, J. E. W. 1935. Desmomyaria. Handb. d. Zoologi~ tung, II, E. a; B: Vertheilg. d. Sal pen. (Kiickenthal), Bd. V, 2. - 1901. Salpidae, Nord. Plankt. 1. Met ca If, M. M. 1918. The Salpidae: A taxonomic study. - 1906. Salpen der deutschen Tiefsee-Expedition., Wiss. U.S. Nat. Mus., Bull. 100, Vol. 2, Pt. 2. Ergebn. der Deut. Tiefsee-Exped. Bd. 12. Russe 11 F. S. and Hastings, A. B. 1933. On the Fa r ran, G. P. 1906. On the Distribution of the Thaliacea Occurrence of Pelagic Tunicates (Thaliacea) in the and Pyrosoma in Irish Waters: Fisheries, Ireland, Sci. Waters of the English Channel off Plymouth. J. Mar. Invest. 1906, 1. Biol. Assoc. U. K., Vol. XVIII, No. 2. Fraser, J. H. 194 ·. The Distribution of Thaliacea (Salps Strei ff, R. 1908. Ober die Muskulatur der Salpen und and Doliolids) in Scottish Waters, 1920-1939. Fisheries, ihre systematische Bedeutung, Zoo!. Jahrb., Abt. f. Syst., Scot., Sci. Invest., 194 ·, No. 1. In the press. Bd. 27. Garst an g, W. 1928. The Morphology of the Tunicata Thompson, H. 1942. Pelagic Tunicates in the Plankton and its bearings on the Phylogeny of the Chordata. of South Eastern Australian Waters, and their place in Quart J. micr. Sci., Vol. 72, Pt. 1. Oceanographical Studies. Commonw. Australia, Council Har an t, H. et Ve r n i ere s; P. 1938. Faune de France, Sci. Indust. Res., Bull. No. 153. Vol. 33, Fasc. 2. Tokio k a, T. 1937. Notes on Salpas and Doliolums occur I h I e, J. E.W. 1912. Desmomyaria. Das Tierreich, Lief. 3~. ring on the Pacific coast of Middle Japan. Annot. Zoo!. - 1927. Thaliacea, Tierwelt N. u. Ostsee, Lief. IX, Tei! Jap., Vol. 16, No. 3. XII a, 2.