A Note Upon a New Zealand Species of Pylaiella
During the course of a study of the algal vegetation of some tide pools at Narrow Neck, Auckland, it was found that in many of the pools there was a small, turf-like, brown filamentous alga which was clearly allied to the genus Pylaiella.
Reference to Laing's List (1926) showed that the only recorded species of Pylaiella in New Zealand was P. ramellosa (Kutz.) Kuck. var. novae zelandiae Grunow based upon a description by Grunow in 1870.
The plants differed from the normal P. littoralis in that some of the reproductive cells were divided longitudinally into two sporangia. Casual reference to Fritsch (1945) suggested that this plant must be very closely allied to, if not identical with, what has been described by Fritsch as the rare P. fulvescens (Schousb.) Bornet.
At our request Professor Fritsch very kindly sent us a description of P. fulvescens extracted from Hamel's Pheophycee de France (1931). This description is as follows (translation):
“Tufts or turf 1·5–3cm. high, composed of prostrate and erect filaments; prostrate filaments with apical growth, irregular, tortuous, fixed by ramifying “crampons”; erect filaments longer, 30–40μ, simple, or with some appearance of branching and attaining the same level, terminating in obtuse ends without formation of a hair; growth at first terminal, then intercalary; cells of the filaments are 1·5 to 2 times longer than wide at the base and at the extremities 4 to 5 times. Cell wall of cellulose and pectin; chromatophores laminated, elongated or in ovoid dises or concentrated, stellate; in the short cells there is only one star, two in the long cells (as in Zygnema). Sporangia unilocular, intercalary, forming a series of 5–20, generally 15, rarely interrupted. They are usually simple but are sometimes divided into two by a longitudinal division; they are 23–33 × 50–65μ zoospores escaping by a lateral pore, very big, 13–19 × 30–45μ, oval, elongated or almost cylindrical, yellowy brown with a colourless beak in front; two cilia, almost terminal, unequal, inserted; eye spot near the beak; zoospores germinate to give long filaments, prostrate but still coloured. Habitat: Rather deep pools well exposed to light at high tide level on rocks and on Patella.”
Subsequently a further account was found in Borgesen's Marine Algae of the Danish West Indies (1920) together with illustrations which agreed completely with our plant (figs. 1 and 2). In the account Borgesen noted that there were creeping filaments from which erect ones arose, the erect ones having an intercalary growing zone near their middle. Some plants possess short rhizoid-like branches. The cells contained a characteristic stellate chromatophore, which was a feature of our plant, one or two such star-like structures being found in each cell, depending on the size of the cell.
Figs. 1 and 2—Pylaiella fulvescens (Schousb.) Bornet. 1a, part of a filament with rhizoids. 1b, part of a filament with sporangia. 2a, b, cells with chloroplasts and nuclei. 2c, part of a fertile filament. (After Borgesen).
The unilocular sporangia were intercalary and the cells somewhat broader than the vegetative cells. In places a few were divided longitudinally into 2 sporangia. Borgesen notes that this plant agreed in all essentials with the one described by Bornet (1889) and Sauvageau (1896) from the Mediterranean.
More recently Lindauer (1948) in a new list of New Zealand Phaeophyceae, has followed Laing in referring this plant to P. ramellosa var. novae zelandiae. Lindauer does, however, point out that there are other forms of Pylaiella, longer and more branched, which are to be found in the south.
Reference to Grunow's (1870) original description yielded the following (translation):
“E(ctocarpus) (Pilayella) littoralis (Dillw.) Harv. var. ? novae zeelandiae.
“Sterile, 1½–2in. high, loosely matted, pale brown turf, whose threads are very similar to the previous variety (var. brasiliensis) and correspond in other respects to Kutzing's picture of Ectocarpus compactus (hardly Ceramium compactum Roth.). Cells 1–2 up to 3 times as long as broad, intermittently arranged side by side. Branching very irregular and sparse. New Zealand.”
From the preceding it seemed evident that the New Zealand plant was identical with that described from the Mediterranean and from the West Indies. The following is a brief account of the New Zealand plant as found around Auckland:
Plants 2–3 cm. high, tufted; erect and prostrate filaments present; prostrate system branched, branches growing out from any cell; growth of erect system intercalary, cells of meristematic region broader than long, 45–48 × 16–18μ; other cells 40–50μ, quadratic; characteristic stellate chloroplast, especially in cells of prostrate system; cells of prostrate system 80–90 × 35–40μ; in older shorter cells of erect sys-
tem chloroplast fills whole cell. Sporangia unilocular and intercalary, occasionally divided longitudinally, occurring in rows, 50–60 × 22–30μ.
Fig. 3—Pylaiella (Bachelotia) novae zeelandiae (Grun.) Setch. 3a, part of thallus showing stellate plastids. × 200. 3b, intercalary growing zone, × 130. 3c, portion of basal rhizoidal region, × 200. 3d, unilocular sporangia, × 130. (Drawn from a recent collection near Auckland.)
It is evident that this plant bears no relation to the English P. littoralis as suggested by Grunow and more recently by Levring (1945). The Campbell Island species of Levring is tufted and grows epiphytically on Callophyllis variegata and, according to Levring, agrees very well with P. littoralis f. rigidiuscula Skotts. (1921) from Fuegia, and it is further suggested that it is probably the same as Laing's P. ramellosa. None of these are identical with the European P. littoralis.
Levring's ideas concerning the relationships of his plant, Skottsberg's and Laing's are probably correct, but in any event Laing's name based on Grunow's would take precedence over the new one proposed by Skottsberg. Skottsberg himself (1901–1903) refers to P. littoralis f. ramellosa and suggests that it is identical with f. novae zeelandiae Grunow.
The small stature, peculiar plastids and the habit of divided sporangia indicate clearly that this plant is somewhat removed from Pylaiella sensu stricto and is more properly referred to the sub-genus Bachelotia Bornet.
P. littoralis sensu stricto exists in a number of varieties, but in all cases the plants are from 2–25 cm. long and our plant rarely exceeds 3 cm.
Further a picture of P. ramellosa (E. littoralis f. ramellosa) is quite unlike our plant (fig. 4). It would appear therefore that our plant is not allied to P. ramellosa, and earlier workers have been mistaken in making this relationship.
The only question that remains to be settled is whether the plant should be called P. fulvescens or P. novae zelandiae. According to Lindauer, Setchell had already realized (private communication) that there was no relation to P. ramellosa or to P. littoralis and he had therefore given it the name P. novae zelandiae.
Reference to the original accounts showed that Grunow's description of P. littoralis f. novae zelandiae was published in 1870 and Bornet's account of P. fulvescens in 1889. It is therefore clear that Grunow's name has priority and that P. fulvescens must become a synonym.
Synonyms and distribution of this particular New Zealand plant (recorded also from other parts of the world) must therefore be as follows:
Pylaiella (Bory) Kjellman
Subgenus: Bachelotia Bornet
Pylaiella (Bachelotia) novae zelandiae (Grun.) Setch.
Conferva fulvescens Schousboe, mscr. Icon. ined. T. 115. in Herb. Thuret.
Ectocarpus fulvescens Thuret in Alg. Schousb., nos. 109–110; Bornet (1889, 1892); Sauvageau (1896).
Pylaiella fulvescens Borgesen (1920); Hamel (1931); Taylor (1937).
Pylaiella ramellosa var. novae zelandiae Laing (1926); Lindauer (1948).
Pylaiella littoralis f. ramellosa Skottsberg (1907).
Pylaiella littoralis f. rigidiuscula Skottsberg (1921); Levring (1945).
Pylaiella novae zelandiae Setch. (mscr. in Herb. Lindauer).
Pylaiella littoralis var. novae zelandiae Grunow (1870).
Distribution: Bermuda, Maine (once reported on Fucus), Morocco, South of France, Spain, Danish West Indies (American Virgin Islands), New Zealand, Campbell Island, Fuegia and northwards.
The wide distribution suggests that this species is not so rare as has been suggested (Fritsch, 1945).
Borgesen, F. R., 1920. Marine Algae of the Danish West Indies, Part III, and Addenda. Dansk. Bot. Ark. 2, 431.
Bornet, E., 1889. Note sur l'Ectocarpus (Pylaiella) fulvescens Thuret. Rev. Gen. Bot., 1, 5.
——, E., 1892. Les Algues de P. K. A. Schousboe. Mem. Soc. Sci. Nat. Cherbourg, 28, 165–172.
Fritsch, F. E., 1945. The Structure and Reproduction of the Algae. Vol. 2. Cambridge.
Grunow, A., 1870. Reise der Osterreichischen Fregatte Novara um die Erde, Bot. Theil, vol. 1, p. 46.
Hamel, G., 1931. Pheophycees de France. Rev. Alg., 1.
Hauck, F., 1885. Die Meeresalgen Deutschland und Oesterreichs, in Rabenhorst's Kryptogamen Flora. Leipzig.
Laing, R. M., 1926. A Reference List of the New Zealand Marine Algae. Trans. N.Z. Inst., 57, 136.
Levring, T., 1945. Marine Algae from Some Antarctic and Subantarctic Islands. Lunds. Univ. Arskrift, N.F. 2, 41 (7).
Lindauer, V. W., 1947. An Annotated List of Brown Seaweeds (Phaeophyceae) of New Zealand. Trans. Roy. Soc. N.Z., 76 (1), 543.
Skottsberg, C., 1907. Zue Kenntnis der Subantarktischen and Antarktischen Meeresalgen. 1. Phaeophyceen. Wiss. Ergebn. Schwed. Sudpolar Exped., 1901–1903, 4. Stockholm.
——, C., 1921. Marin Algae. 1, Phaeophyceae. Botanische Ergebn. der Schwed. Exp. nach Patagonien und der Feuerlande (1907–1909). K. Svenska Vet. Akad. handl. 61. Stockholm.
Taylor, W. R., 1937. Marine Algae of N. Eastern Coast of N. America. Univ. Mich. Press, p. 105.