HEMICHORDATA ENTEROPNEUSTA Family: Ptychoderidae TORNARIA LARVAE (By C. Burdon-Jones)')

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1 CONSEIL INTERNATIONAL POUR L'EXPLORATION DE LA MER Zooplankton. Sheet 70. HEMICHORDATA ENTEROPNEUSTA Family: Ptychoderidae TORNARIA LARVAE (By C. Burdon-Jones)') 1967 l) With grateful acknowledgement to G. W. and G. S t i a s n y.

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3 -3- For identification and population analysis it is convenient to sub-divide the various Tornariae into 6 age-groups or stages of development as follows: 1. M ii 1 1 e r (Figs. 2, 3) newly hatched, with pre- and post-oral ciliary s. 2. H e i d er (Fig. 4) as for Miiller, with telotroch but devoid of and. 3. M e t s c h n i k o I f (Figs. 5-7) with developing or fully developed and. 4. K r o h n (Figs. 8-11) with developing or fully developed secondary and and secondary telotroch; maximum size. At this stage the specific features of the tornaria can be identified with certainty. 5. S p e n g e 1 (Figs ) with regression of secondary and, and diminution in size. 6. A g a s s i E (Fig. 16) advanced regression of all ciliary tracts, elongated longitudinally, metamorphosis imminent. All these stages are planktonic and lecithotrophic, with the probable exception of late Agassiz larvae. Balanoglossus clavigerus (S. d e C h i a j e, S t i as n y, 1914 a and b) is the only North Atlantic species for which all the six develop mental stages are known. The specificity of all other North Atlantic Tornariae is based on the characteristics of their Krohn stages. Their identification with an adult species is tentative and based primarily on their relative geographic distribution : Tornaria bournei is probably the larva of Glossobalanus sarniensis Tornaria mielcki is probably the larva of G. marginatus M e e k Tornaria meeki - adult unknown. Stage L Miiller (Fig. 2) (Fig. 3) stage 11. Heider Balanoglossus clavigerus (Fig. 4) Form Ciliary. s.. - Oral Dorsal - lobe H ydrocoel dumb-bell shaped, slightly compressed laterally completely arched, very small, present ca. 0.3 similar incompletely arched, not large, ing Form Ciliary s telotroch Dorsal lobe ca ovoid present, and er than ciliary s strongly arched and Miiller stages have not been described for Tornaria meeki and T. mielcki. Heider stages have not been described for any other Tornariae. Fig. 1. Typical Tornaria larva, a. general anatomy, b. Mercator pro- Advanced K r o h n Stage: jection and nomenclature of ciliary tracts. Fig. 8,, a. dorsal, b. lateral. Miiller Stage: Fig. 9,, ventral. Fig. 2,, a. lateral, b. ventral. Fig.10, T. meeki, ventral. Fig. 3,, lateral. Fig.11, T. mielcki, a. ventral, b. dorsal. Heider Stage: Spengel Stage: Fig. 4,, lateral. Fig.12,, a. lateral, b. ventral. Me tsc hn i k off Stage: Fig.13,, ventral. Fig. 5, B. clauigerus, a. young stage, lateral, b. ventral, Fig.14, T. meeki (Spengel-Agassiz stage), dorsal. c. advanced stage, dorsal. Fig.15, T. mielcki, a. ventral, b. apical. Fig. 6, T. boumei, a. young stage, ventral, b. advanced stage, Agassiz Stage: lateral. Fig.16, B. clavigerw, lateral. Fig. 7, T. meeki, advanced, lateral. (Figures not all to same scale) Figs.2, 4, 7, 10, 12, 13, 14, 16 after G. W. and G. S t iasny, 1925; Figs. 3, 6, after G. C. B o U r n e, 1889.

4 ~ -4- Young Stage 111. Metschnikoff (Figs. 5a, b) (Fig. 6a) Advanced Stage 111. Metschnikoff (Fig. 5c) (Fig. 6b) T. meeki (Fig. 7) ciliary Post-oral ciliary arched distinctly tri-lobed and ca flattened very and Secondary and smaller than ssddle smaller than and very arched mid-ventrally long and latero-ventrally short, ening ventrally Inferior dorsal Anal moderately wide laterally dorsally directed very laterally dorsally directed very latero-ventrally Anal telotroch Heart vesicle not or flanged and flanged Coelomic sacs Hydrocoel Heart vesicle small large medium? No Metschnikoff stages have been described for Tornana mielcki, and only advanced stages of T. meeki. stage IV. Kroha (Figs. 8a, b) (Fig. 9) T. meeki (Fig. 10) T. mielcki (Figs. lla. b) Size, height in mm Diameter of telotroch Median preand postoral leas than heizht 4 secondary moderately deep and less than height 5 moderately deep less than height 3, median one, all shallow or more and deep er than median, 3 secondary er than median, 3-4 secondary er than median, 2 shallow secondary almost equal to median 4, very deep secondary internally, 2-3 deep externally as as high, apex mid-ventral or posterior as in B. clavigerw higher than, apex about mid-ventral higher than, apex anterior to mid-ventral point, lobed Inferior dorsal lobe curved only slightly curved not curved very strongly curved

5 ~ -5- Stage v. Spengel Secondary and Median s Mid-gut Intestine Coelomic sacs Oral Inferior dorsal lobe (Figs. 12a, b) 2 or or present ly arched er than, cylindrical elongated and 2 pairs no regression (Fig. 13) 2 or present, anteriorly extended very much er than massive, spherical globular 1 pair very, expanded very T. meeki (Fig. 14) 1.75 present, but very shallow, anteriorly extended very much er than ovoid, but not large sub- and short 1 pair no regresaion T. mielcki (Figs. 15a. b) 2, regression advanced slightly lobed, anteriorly extended equal to massive, spherical globular and flattened 1 pair very no regression Shape Anal Field 3addles Buccal cavity H ydrocoel Coelomic sacs Mid-gut Intestine I elongated, with annular constriction marked 1 y very, devoid of secondary and flexed posteroventrally very large 2 pairs elongated and cylindrical elongated and T. meek (Fig. 14) slightly more elongate than Krohn etage, with secondary and some flexure large 2 pairs globular - woid The Agassiz stage is only known for. The details given for T.meeki are for the transitional stage Spengel-Agassiz. Distribution of larvae E. clavigerus - English Channel. - English Channel (Eddystone, Falmouth, Plymouth Sound) : Ireland (Valencia Harbour)., : Irish Sea (Port Erin) : North.Sea (Dogger). T. meeki - North Sea (St. Andrews, Longstone, Helgoland). T. mielcki - North Sea (Longstone) ; Celtic Sea. Tornaria sp. incert. - Off west coast of Ireland: Skagerak. Distribution of adults - English Channel (French coast). Glossobalanus sarniemis ( = T. boumei?) - English Channel (Channel Ia, Scilly Is., Plymouth) ; S. W. and North Ireland; North Sea; Kattegat. C. marginatus (= T. mielcki) - North Sea (Fame k) ; Kattegat Further Information on Identification a. Larvae. i. General: Stiasny-Wynhoff & Stiasny, 1926, v. T. mielcki: P e a c o c k, 1923, pp , Fig. 2. S t i as n y, ii. E. clavigerus: H e i d e r, 1909, pp , Figs , pp.14-7, Figs.1-7. Stiasny-Wynhoff 8 S t iasn y, 1914a. p. 62, Figs. W & X, PI. IV, Figs. 12, 13, S t i a s n y, 1927, pp , Fig. 68, pp , Fig. 74. P1. V, Figs ; 1914b, P1.6, Figs S t i a s n y - Wynhoff & Stiasny, 1927, pp , Figs.5-8. b. Adults. iii. : Bourn e, 1889, PI. 7, Figs. 1, 4, P1.8, Fig. 13. i. General: H o r s t, Johnstone et al., 1924, Pl.VI1, Fig.lO. Stiasny. ii. : C h i a j e, , pp , Fig.6; 1926, pp , Figs iii. Glossobalanus sarniensis: B U r d o n - J o n e s, Stiasny-Wynhoff & Stiasny, 1927, pp , iv. C. marginatus: M e e k, Figs. ~~ 61-43, pp , Figs. 69, 70, pp , Figs c. General Biology. iv. T.rneeki: Meek, 1922, pp , Fig.14. S tiasny, 1925, pp , Figs.l-6. Stiasny-Wynhoff & H o r s t, , 1925, S t i a s n y, 1927, pp , Fig. 67, pp , Figs. 71 B u r d o n - J o n es, ,

6 - 6 - References Bourne, G. C, i889. J. Mar. biol. Ass. U.K., 1, B U r d o n J on es, C., Nature, Lond., 172, B U r d o n - J o n e s, C., Handbuch der Zoologie, Erganzungslieferung zum Bd. 111, 2 Halfte, Bd. V, 1 und 2 Johnstone, J., Scott, A., & Chadwick,H. C., The Marine Plankton, pp Liverpool. M e e k, A., Quart. J. micr. Sci., 66, P e a c o c k, A. D., Rep. Dove Mar. Lab., Cullercoats, Halfte. 12, C h i a j e, S. d e, Mem. Anim. vertebre Regno Napoli, S t i as n y. G., Z. wiss. Zool., 110, , b. Mitt. zool. Stat., Neapel, 22, Heider, K., Zool. Am., 34, 695-7M Vid. Medd. Dansk. Naturh. Foren., Copenhagen, H o r s t, C. F. v a n d e r, Tierwelt Nord- und Ostsee, 73, VIIa Z. wiss. Zool., 125, Horst, C. F. van der, Bronns Klassen, 4, Zool. Am., 68, Abt. 4, Buch 2, Teil 2. Stiasny-Wynhoff, G., & Stiasny. G., Zool. H o r s t, C. F. van d er, Handbuch der Zoologie, Am., 68, Bd. 111, 2 Halfte Ergebn. Zool., 7,

CLUPEOIDAE (BY ALAN SAVILLE)

CONSEIL INTERNATIONAL POUR L EXPLORATION DE LA MER Identification Sheets on Fish Eggs and Larvae Sheet 1 CLUPEOIDAE (BY ALAN SAVILLE) 196 -2 - la 2a 2b 2c PLATE I 1. Anchovy; a, 6 mm; b, 11 mm; c, 25 mm.