MARINE BIOLOGICAL ASSOCIATION OF INDIA MEMOIR II THE DINOPHYCEAE OF THE INDIAN SEAS Part 2. Family PERIDINIACEAE Sch'utt emend Lindemann BY R. SUBRAHMANYAN Retired Scientist, Central Marine Fisheries Research Institute. 1971 MARINE BIOLOGICAL ASSOCIATION OF INDIA COCHIN-11. INDIA. © Copyright 1971 MARINE BIOLOGICAL ASSOCIATION OF INDIA COCHIN. 11. Printed at Arul Printing Works, 3, Antony Street, Madras-14. Published by AHH0|Hi|fel|A1arine Biological Association of India, Gopala Prabhu Cross Road, Cochin-ll, India. DEDICATED TO DR. S. JONES, Founder . President, MARINE BIOLOGICAL ASSOCIATION OF INDIA. PREFACE TO PART II Family PERIDINIACEAE (SchUtt) emend Lindemann In this second part of The Dinophyceae of the Indian Seas, species under them of the Family Peridiniaceae from the Indian Ocean region are described, comprising the genera Diplopsalis Bergh, Peridiniopsis Lemmermann, Preperidinium Mangin, Diplopeltopsis Pavillard, Diplopsalopsis Meunier and Peridinium Ehrenberg. The account deals with the original work of the author and those of earlier workers reproduced here duly acknowledged. One hundred marine species and eighteen fresh, water forms from the region are dealt with ; seven insufficiently known are mentioned. A list of species exclusively (so far) recorded from other seas and oceans is given. Over 50% of known Peridiniaceae occur in the Indian Ocean waters. The authoristhankful to his colleagues Mr. C. P. Gopinalhan and Mr. C. Thankappan Pillai for invaluable help with figures and typing of the MSS and Mr. K. Rengarajan for verification i to Dr. M. Vanuucci, UNESCO Curator at the Indian Ocean Biological Centre, IIOE, for translation of Spanish literature; and Dr. S. Jones, President of the Marine Biological Association of India for help with the publication of this series of studies. The author owns full responsibility for defective proof­ reading which has necessitated an errata list and he hopes that this will not detract the value of the work to users. 52. CHOOLAI HIGH ROAD R. SUBRAHMANYAN MADRAS-7. INDIA CONTENTS Preface to Part 2 ... i Family PERIDINIACEAE SchUtt emend Lindemann ... 1 Genus Diplopsalis Bergh ... 3 Genus PerWi/»fops/s Lemmermann ... 5 Genus Preperidinium Mangin ... 5 Genus Diplopelta Jorgensen ... 7 Genus Diplopeltopsis Pavillard ... 8 Genus Diplopsalopsis Meunier ... 9 Genus Entzia Lebour ... 9 Genus Heterocapsa Stein ... 9 Genus Minuscula Lebour ... 10 Genus Peridinium Eherenberg ... 10 Classification , ... 17 Section Tabulate Jorgensen ... 22 Section .<4t;e//ana Paulsen ... 24 Section Monovela Ab6 ••• 24 Section £:«;cen(r/CO Paulsen ... 28 Section Humili-Piriformia Paulsen ... 29 Section Pellucida Jorgensen ... 48 Section Conica Jorgensen ... 65 Section Oceanica JSrgensen ... 79 Section Divergentia Jorgensen ... 86 Insuificiently known species ... 95 Species recorded from Antarctic^ Argentina Sector, possibly occuring in the Indian Sector «« 96 Annexure I: Freshwater Species ••• 104 Taxa occuring in the Indian Ocean ... 114 Taxa known exclusively from areas other than Indian Ocean ... 117 Bibliography ••• 120 Plates ••• 155 Index ••• 315 Family PERIDINIACEAE SchUtt emend Lindemann, 1928 Cells spherical to longish; small horns often on the hypotheca. An apex present or absent. Girdle circular or spiralled, right-handed (dextral) or left-handed (sinistral). Theca thin in the younger stages, later becomes thick and strong; consists of variously shaped plates. Tabulation variable, malformation cdramoft. Difficult to set up valid plate patterns for mein- bers of the family. Mostly there are 6 to 7 precingulars, 5 to 6 post- cingulars and two antapical plates which may be fused in Diplosalis. Tabu­ lation of epitheca more variable than that of hypotheca. Surface of theca sculptured with areoles, papillae, spines, lists or pores; seldom smooth. Plasma of marine species at times coloured. Stigma present or absent; when present sometimes pale; rarely present in freshwater species. Pusules occur in marine species. Chromatophores greenish yellow or brown, present often in large numbers, at times with pyreiioids. Starch, fatty substances &fid rods (rhabdosomes) constitute inclusions. Nucleus round or elon­ gated. Cells rarely form colony. Cysts formed after casting off of theca. Not much known about reproduction. Size varies froni 18 to 300 /A. In fresh, brackish and marine habitats. The plate-pattern on the cells is an important taxonomic character for diagnosis of genera and species. The plates composing the body of the cell are arranged in rows parallel to the girdle for convenience in designation. The terminology of Kofoid (1909 a) is widely accepted for this purpose. On the epitheca, the plates around the apex are called the apicah. Anterior to and touching the girdle is a row of plates, the precingular series. Another group in contact with the apex, is the apical series. Between these two plates may be found interpolated plates called anterior intercalaries. The girdle also is made up of a series of plates not well known and hence usually omitted in the formulae. On the hypotheca, bordering the girdle, is a row of plates known as postcingular series. Another series, which touches the antapex is termed antapical plates. Between these and postcingulars, there may be interpolated the posterior intercalaries. Kofoid (/. c.) uses prime signs to designate the plates which is adopted by most workers. Graham (1942) has proposed use of letters to denote them. The two are given below:— Plates Kofoiii Graham Apical platelet pl Apical plate V, 2' ..A' ap Anterior intercalary a a Precingular 1", 2" 7" pr Girdle g Postcingular r",...2"'...5"' po Posterior intercalary posterior intercalary p Antapical 1"", 2"", ... ant Sulcal s e. g. The plate formula for Perid'nium Ehrenberg would be: Lebour: 4' 3a 7" 5'" 2"" Sfchiller: 4' 2-3a 7" 5'" 2"" Graham: 2-5ap; 0-8a; 6-7pr; 3-6g; 5-6s, 5-6po; Op, 2ant. The additional details in Graham's formula is due to knowledge accrued since Schiller. As most of the workers adopt Kofoid's signs, the same is employed here to help easy reference. Lindemann (1928) merged some of the genera of earlier authors into Diplosalis and Schiller (1937) merged some into Glenodinium and some into Peridinium. Investigations since 1937 tend to show that several of the genera merged by these authors can be accorded independent status (Loeblich et al 1966). Thus nine genera are recognized in the family Peri- diniaceae distinguished by the following characteristics. Diplopsalis Bergh, 1881 Cells lens-shaped with a left long list fairly conspicuous. Plate formula 3' la 6" 5'" 1"". The plate here called the anterioi- intercala­ ry may be displaced apical. Apical pore present. Marine and in relict seas. Peridiniopsis Lemmerman, 1904 Cell with plate formula: 3'lo 6" 5'" 2"". Round conical or lenti­ cular. Like D plopsalis but with two antapicals. The large anterior inter­ calary may, however, be displaced apical. Diplopelta Jorgensen, 1912 Two antapicals, second small anterior intercalary plate. Formula: 3' 2a 6" 5'" 2"". Diphpehopsis Pavillard, 1913 Cells lens-shaped. Plate formula: 3' 2a 7" 5'" 1"" or the large intercalary apical, 7 precingulars and 1 antapical; otherwise like Diplopelta. Entzia Lebour, 1922 Plate formula : 4' l-2a 7" 5'" 1"". Apical pore present. Differs from Peridinium subgenus Archaeperidinium in having only one antapical plate and sometimes, only on? antsrior intercalary. Displopsalopsis Meunier, 1909 Cells lens-shaped. Plate formula: 3' 2a 7" 5'" 2"" or 4" \a 7" 5'" 2"". Like Diplopeltopsis but with 2 antapicals. Heterocapsa Stein, 1883 Cells more or less spindle-shaped. One antapical drawn out into a horn. Plate formula: 4ap2a6 for 5 pst op 2 at (4' 2a 6' 3'" 2"".) Peridinium Ehrenberg, 1832 Shape variable, round ellipsoidal or spindle-shaped, and dorsiven- traliy compressed. 2-5', O-83, 6-7" (3-6 ? g), 5 (-6)'" op 2"". Preperidinium Mangin, 1913 Ellipsoidal or spherical cells Tabulation: 4' la 7" 5'" 1"" or 4' la 5-6" 5'" 1"". One of the apical plates very much to the left. Genus Diplopsalis Bergh, 1881 Bergh, 1881 a. Paulsen, 1908, p. 34. Lebour, 1925, p. 99. Lindemann, 1928, p. 90. = Glenodinium Pouchet, 1883, in part. = Peridinium Ehrenberg, Paulsen, 1908, p. 41, in part. Shape of cells globoid or, sphaerical, flattened pole to pole. Apical pore present, generally slightly marked, peg like. Girdle equatorial, circular; there appears to exist an inclination to the right sometimes. Sulcus doe$ not extend on to the epitheca, always accompanied by a characteristic winged list on, the left margin, which can extend over the antapex. Plate formula : (3-4ap; 0 - 2a; 6 -Ipr;! g; 5 postcingular; Op; I • lat); 3-4'; 0-2a; 6-7";? g; 5'"; 0/»; 1-2"". Shell surface smooth or finely punctate; in freshwater forms also areolated. Large sack pusule (according to SchUtt besides a small retort­ like or round collecting pusule with zone of very small, tiny tubes in •them, dattghter pusules). Chromatophores apparently absent. According to SchUtt, the outer marginal layer of marine forms is coloured often pink^ Length between 30 to 50/t; diameter 30 - 90/x. Marine; one species freshwater. Diplopsalis lenticula Btxgh, 1881 (PI. I, figs. 1-3,5, 7-9, 16; III, fig 1, 2, 3, 8, 10) Bergh, 1881, p. 244, figs. 60 - 62. Stein, 1883, pi. 8, figs. 12 • 14; pi. 9, figs. 1, 2 (?). Schiitt, 1895, pi. 15, fig. 50. Paulsen, 1908, p. 35, fig. 44. Lebour, 1922, p. 795, figs. 1 - 5; 1925, p. 99, pi. 15, figs. 1 a - e. Matzenauer, 1933, p. 453. Wood, 1954, p. 222, fig. 86 a - e. = Glenodinium lenticula (Bergh) Schiller, 1937, p. 103, fig. 95 a - /i; Kisselev, 1950, p. 136, fig. 217 a • e. = Diplopsalis sphaerica Meunier, 1909. Cells lens - to globular-shaped. Epitheca and hypotheca equal, former with short apical horn. Girdle circular, median. Girdle membrane supported by fine prongs. Sulcus generally reaching neighbourhood of posterior end; its left margin with conspicuous, hyaline list, which in ventral view projects like a process towards the right. Chromatophores absent. Plasma coloured pink, or lightly purple.