An Epiphytic Species of Jania (: Rhodophyta) Endemic to Southern Australia

Sophie C ~ucker,* J. Donna LeBlanc and H. William JohansenC

A Botany School, University of Melbourne, Parkville, Vic. 3052. Department of Systematics and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06268, U.S.A. Department of Biology, Clark University, Worcester, Massachusetts 01610, U.S.A.

Abstract Ducker, S. C., LeBlanc, J. D., and Johansen, H. W. An epiphytic species of Jania (Corallinaceae: Rhodophyta) endemic to southern Australia. Contrib. Herb. Aust. 17: 1-8, 1976. Mostly on the basis of conceptacular features, the name Jania pusilla (Sonder) Yendo is confirmed for a species also known as Corallina nana Harvey or Corallina lenormandiana DeToni. J. pusih is a short plant with a crustose base; it has broad intergenicula, large conceptacle chambers, and the largest tetrasporangia known for articulated corallines. These plants are endemic to southern Australia where they occur on certain species of Cystophora.

INTRODUCTION The southern Australian coast is rich in endemic algae and seagrasses, many of which have characteristic epiphytes. This is particularly true of the members of the Fucales, which carry a rich flora of host-specific algae. The widely distributed genus Cystophora has several coralline epiphytes. This paper describes a small articulated coralline alga, Jania pusilla (Sonder) Yendo, which occurs in profusion on certain species of Cystophora. The alga now known as J. pusilla was first described by Harvey (1863, synop. p. 29) as Corallina nana Lenormand. However, Sonder (1880, p. 21) realized that C nana was a later homonym of a name published by Zanardini (1844, p. 1024) for plants from Dalrnatia, and he renamed the Australian epiphyte Corallina pusilla. Another name, Corallina lenormandiana Grunow, was published by De Toni (1905, p. 1851). In the same year, Yendo (1905, p. 39) tentatively assigned the alga to the genus Jania. Mainly on the basis of conceptacular characteristics, the combination Jania pusilla (Sonder) Yendo is confirmed. The following synonymy and references apply:

Jania pusilla (Sonder) Yendo, J. Coll. Sci. Imp. Univ. Tokyo 20: 39. 1905. Corallina ?nana Lenormand in Harvey, Phycol. Austral. 5: synop. 29. 1863 (non Corallina nana Zanardini); Tisdall, Rep. 7th Meet. Aust. Ass. Adv. Sci.: 508. 1898; Wilson, Proc. R. Soc. Vic. 4: 176. 1892. 2 S. C. Ducker, J. D. LeBlanc and H. W. Johansen

Fig. 1. Plants of Janta pusilla on Cystophora siliquosa. Lorne, Victoria. (Ducker, 30.x.1970; MELU 20576.) Fig. 2. Janta radiata on Sargassum sp. Enoshirna, 1901. (Okamura, Alg. Jap. Exsic. No. 83; BM.) Scale in mm. Fig. 3. View of a single base of Janta pusilla bearing numerous fronds. San Remo, Victoria. (Ducker, 21.v.1972; MELU 21427.) Fig. 4. Jania pusilla. Pt Lonsdale, Victoria. (Ducker, 30.v.1963; MELU 543.) Scale in mm. A Jania from Southern Australia 3

Corallina pusilla Sonder in F. Muell., Fragm. Phytogr. Austr., Suppl. ad Vol. 11: 21. 1880; Lucas, Proc. Linn. Soc. N.S.W. 34: 57. 1909, 37: 164. 1912; Tisdall, Rep. 7th Meet. Aust. Ass. Adv. Sci.: 508. 1898. Corallina lenormandiana Grunow ex De Toni, Syll. Alg. Omnium Cognit. 4, sect. 4: 1851. 1905; Lucas, Proc. Linn. Soc. N.S.W. 37: 165. 1912; Lucas and Perrin, Seaweeds S. Aust. 2: 400. 1947; Womersley, Trans. R. Soc. S. Aust. 73: 167. 1950.

MATERIALS AND METHODS The plants obtained were preserved in alcohol or dry. Paraffin-embedded material was sectioned at 8 pm and stained with haematoxylin, or plants were decalcified whole in 5% trichloroacetic acid and stained in various ways. Specimens of (L.) Lamx and Jania adhaerens Lamx were collected in Great Britain and South Africa respectively.

Fig. 5. The initiation of a new intergeniculum and geniculum in Jania pusilla. (MELU 21427.) Fig. 6. A fully developed geniculum in longisection. Same scale as in Fig. 5. (MELU 21427.)

RESULTS The following features characterize Jania pusilla: Substratum: upper parts of Cystophora spp. (Figs 1 and 4). Plant bases: pulvinate crusts to 1 mm diameter (Fig. 3). Fronds: in tufts, up to 12 per base, to 1 cm long (Figs 3 and 4). Branch- ing: dichotomous at irregular intervals (Figs 4 and 10). Intergenicula: subterete to compressed, cuneate, 400-1200 pm long, 200-500(-700) pm broad in distal parts (Figs 9, 9 and 10). Genicula: 130-200 pm long, 50-200 pm broad (Figs 4 and 6). S. C. Ducker, J. D. LeBlanc and H. W. Johansen

Fig. 7. Part of a frond of Jania pusilk showing tetrasporangial conceptacles. (MELU 543.) Fig. 8. Part of a tetrasporangial plant of Jania rubens. Roundstone Bay, near Galway, Ireland. (Johansen, 29.iv.1972.) Fig. 9. Part of male plant of Jania pusilk. (MELU 21427.) Fig. 10. Female frond of Jania pusilk showing procarpic (P)and carposporangial (C) conceptacles. Pt Danger, Portland, Victoria. (Ducker, 13.viii.1968; MELU 3831.) A Jania from Southern Australia 5

Fig. 11. Longisection of intergeniculum with young male conceptacle. (MELU 21427.) Fig. 12. Male conceptacle. (MELU 21427.) Fig. 13. Whole mount of procarpic conceptacle. Georgetown, Tasmania. (Mueller in Kew.) Fig. 14. Section of carposporangial conceptacle showing fusion cell (arrow). Carposporangial fdaments are lacking. San Remo, Victoria. (Ducker, 21.v.1972; MELU 21431.) 6 S. C. Ducker. J. D. LeBlanc and H. W. Johansen Tetrasporangial conceptacles: single in slightly broadened upper parts of intergeniculum, not swelling markedly, chamber diameter 350450 pm, fertile intergenicula branching (Fig. 7). Tetrasporangia: fewer than 10 undergoing cytokineses in a conceptacle, 200-350 pm long, 100-130 pm diameter (Fig. 7). Sexual plants: dioecious. Sperma- tangial conceptacles: fertile intergenicula devoid of surmounting branches, conceptacles lanceolate, chamber 130-230 pm diameter, 350-500 pm high, sterile canal about 100 pm long (Figs 9, 11 and 12). Procarpic conceptacles: chambers 100-200 pm diameter (Figs 10 and 13). Carposporangial conceptacles: fertile intergenicula branched, branches often fertile, chambers 350-450 pm diameter; fusion cell usually with con- vex upper surface, 12-25 pm thick, 80-130 pm diameter, sporangia 100-130 pm diameter, carposporangial filaments arising from margin of fusion cell (Figs 10 and 14). Type locality: 'Parasitical on various C'ystophorae. Port Fairy.' (Victoria, Australia) (Harvey 1863, synop. 29). Lectotype: Harvey 452D (MEL 501722). Epiphytic on C'ystophora siliquosa. Distribution: Jania pusilla is restricted to the host Cystophora; it is found mainly on C siliquosa J. Ag. and C monilgera J. Ag., but occasionally on C. congesta Womersley & Nizamuddin and C subfarcinata (Mertens) J. Ag. The distribution broadly follows that of C siliquosa, from Port Denison, Western Australia, to Wilson's Promon- tory in Victoria, the Bass Strait Islands and northern Tasmania (Womersley 1964).

DISCUSSION The features characteristic of the genus Jania have been described by Suneson (1937), Segawa (1946), Ganesan (1965) and Johansen (1970) and are primarily: (1) main branching dichotomous; (2) thick, narrow fusion cell bearing marginal carposporangial filaments; (3) spermatangial conceptacles long and narrow with high ceilings and short canals; (4) fewer than 10 mature tetrasporangia per conceptacle; and (5) intergenicula containing tetrasporangial and carposporangial conceptacles pro- ducing surmounting branches. In contrast, Corallina has pinnate branching; thin, broad fusion cells; broad spermatangial conceptacles with low ceilings and long canals; and more than 10 tetrasporangia in each conceptacle (Johansen 1972). J. pusilla has all of the characteristics of Jania, and differs from J. rubens (Fig. 8), the fiist- described species in the genus, and from J. adhaerens, a common epiphytic species, primarily on morphological grounds (Table 1). Contrasting with the shortness (< 1 cm) of J. pusilla are the broad intergenicula in this species relative to the narrow ones in other species of Jania. This breadth is reflected in the greater size of conceptacle chambers and in the massive sporangia, which are larger than any before reported for articulated . J. radiata (Yendo 1902) appears to be closely related to J. pusilla, although the whereabouts of its type is unknown. Examination of other collections (Fig. 2), and a paper by Segawa (1946), lead to the conclusion that this species is closely related to J. pusilla, differing only in the smaller intergenicula (< 150 pm broad). The types or other authentic specimens of several other small species were studied and found to differ significantly from J. pusilla, mostly in having intergenicula less than 200 pm in diameter. In addition to J. rubens, J. adhaerens and J. radiata, the following were compared to J. pusilla: J. capillacea Harvey; J. compressa Lamouroux; J. gibbosa Lamouroux; J. pumila Lamouroux; J. pygmaea Lamouroux; J. tenella var. zacae A Jania from Southern Australia 7

Table 1. Essential differences among three species of Jania

- - --- Jnnia rubens Jania pusilla Janiu adhaerens

Frond length (cm) up to 3 Intergenicular length (pm) 400-900 Intergenicular width (pm) 100-180 (upper parts) Branching angle narrow narrow wide Base in mature plants stoloniferous crustose stoloniferous Chamber diameter, 150-250 350-450 150-250 tetrasporangial conceptacle (pm) Tetrasporangium length Ocm) Fusion cell diameter Otm) Carposporangium diameter (pm)

Dawson; J. tenuissima Sonder in Lehrnann; J. ungulata (Yendo) Yendo; J. ungulata f. brevior (Yendo) Yendo. Authentic material of Corallina mm Lenormand at CN has been compared with Corallina lenonnandiana De Toni at W. The type of Corallina nana Zanardini (1844) at Venice belongs to Corallina as currently understood (Johansen 1970). Several articulated corallines exhibit host specificity; for example, J. rubens occurs mainly on Cladostephus sp. (Phaeophyceae: Sphacelariales) in the British Isles (Duerden and Jones 1974), some species of Metagoniolithon occur mostly on sea- grasses in Australian waters, and J. radiata in Japan appears to occur mostly on Sargassum sp. The last example is interesting in that both the closely related J. radiata and J. pusilla grow on host plants in the Fucales.

ACKNOWLEDGMENTS We are indebted for help in the following herbaria: BM, CN, HBG, MEL, PC, W and Venice. Dr Roger Meslin aided in understanding Lamouroux specimens, and Dr P. C. Silva clarified nomenclatural issues. The study was undertaken while one of the authors (J.D.L.) was sponsored by a National Science Foundation Undergraduate Research Program at Clark University. The first author (S.C.D.) acknowledges support by the Australian Research Grants Committee.

REFERENCES De Toni, G. B. (1905). 'Sylloge Algarum omnium hucusque Cognitarum.' Vol. 4, . Sect. 4. pp. 1522-973. (Padua.) Duerden, R. C., and Jones, W. E. (1974). The host specificity of Janiu rubens (L.) Lamour. in British waters. VIIIth International Seaweed Symposium Bangor. p. A36. Ganesan, E. K. (1965). Studies on the morphology and reproduction of the articulated corallines. I. Phykos 4, 43-60. Harvey, W. H. (1863). 'Phycologica Australica.' Vol. 5, plates 241-300; synop., pp. 1-73. 8 S. C. Ducker, J. D. LeBlanc and H. W. Johansen

Johansen, H. W. (1970). The diagnostic value of reproductive organs in some genera of articulated coralline . Br. Phycol. J. 5, 79-86. Johansen, H. W. (1972). Conceptacles in the Corallinaceae. Proc. 7th Int. Seaweed Symp., Sapporo, Japan, 1971. (Ed. K. Nisizawa.) pp. 114-19. Segawa, S. (1946). Systematic anatomy of the articulated corallines. X. Jania radiata Yendo. Seibutsu 1, 151-6. Sonder, 0. G. (1880). Algae Australianae hactenus cognitae. In F. von Mueller, 'Fragmenta Phytographiae Australiae'. SuppL ad Vol. XI. pp. 1-42, 105-7. Suneson, S. (1937). Studien Uber die Entwicklungsgeschichte der Corallinaceen. Lunds Univ. Arsskr. Avd. 2, 39(9). Womersley, H. B. S. (1964). The morphology and taxonomy of Cystophora and related genera (Phaeophyta). Aust. J. Bot. 12, 53-110. Yendo, K. (1902). Corallinae verae Japonicae. J. Coll. Sci Imp. Univ. Tokyo 16, 1-36. Yendo, K. (1905). A revised list of Corallinae. J. Coll. Sci. Imp. Univ. Tokyo 20, 1-46. Zanardini, G. (1844). Corallinee. EncicL Ital., Venezia, Tasso. 6, 1013-36.