Fushitsunagia catenata

D’Archino, Roberta & Zuccarello, Giuseppe C., 2021, Two red macroalgae newly introduced into New Zealand: Pachymeniopsis lanceolata (K. Okamura) Y. Yamada ex S. Kawabata and Fushitsunagia catenata Filloramo et G. W. Saunders, Botanica Marina (Warsaw, Poland) 64 (2), pp. 129-138 : 131

3.2.2 Fushitsunagia catenata ( Figures 17–24 )

Thalli grew in erect clumps, 11–14 cm in height, and were red to purple in colour. The cylindrical primary axes attached by discoid holdfasts to the substratum ( Figure 17 ). Branching of axes was alternate or opposite at regular intervals, the branches were slightly constricted at the nodes, with straight apices ( Figures 18, 20 , and 23). The texture of the thalli was turgid throughout. Axes were about 1 mm wide, hollow, and composed of 6–10 layers of cells ( Figure 19 ). The cortical cells were closely packed and consisted of periclinally elongated ovoid cells, 13–15 × 7– 9 µm. The medullary cells were 23–39 × 16–19 µm. Cystocarps were globose, nearly sessile, and produced in small groups or singly along the main and secondary axes, globose and nearly sessile, 800–950 µm in diameter and surrounded by a smooth firm ostiolate pericarp ( Figures 20–22 ). Tetrasporangia were tetrahedrally divided and formed in patches (460–912 × 180–400 µm) on the upper branches which become swollen ( Figures 23 and 24 ). A further detailed description of this species as Lomentaria catenata is provided by Lee (1978).

Figures

Figures 17–24: Fushitsunagia catenata. Habit, vegetative and reproductive morphology. (17) A tetrasporic specimen collected in Lyttelton harbour (WELT A034384). Scale bar = 2 cm. (18) Alternate clavate branches of a tetrasporangial specimen (WEL A034384). Scale bar = 1 mm. (19) The abrupt transition between sub isodiametric cells of the pseudoparenchymatous inner cortex and the two or three layered outer cortex (WELT A034384). Scale bar = 20 μm. (20) Irregular branching of a cystocarpic specimen (WELT A034383). Scale bar = 1 cm. (21) Clustered sessile and basally constricted globose cystocarps (WELT A034383). Scale bar = 1 mm. (22) Surface of an ostiolate pericarp (WELT A034383). Scale bar = 1 mm. (23) Alternate or opposite branching of a tetrasporic specimen (WELT A034382). Scale bar = 1 cm. (24) Tetrasporangia encircling the inside margins of wide sorus opening (WELT A034382). Scale bar = 1 mm.