Jania sphaeroramosa Twist, J.E.Sutherl.

Twist, Brenton A., Sutherland, Judy E. & Nelson, Wendy A., 2018, Epiphytic Jania in New Zealand: Jania sphaeroramosa sp. nov. (Corallinales, Rhodophyta), Phytotaxa 357 (1), pp. 30-40 : 32-35

Jania sphaeroramosa Twist, J.E.Sutherl. & W.A. Nelson, sp. nov. ( Figs 3–13 )

Type:— NEW ZEALAND. South Island: South East Otago, Waipapa, mid intertidal, exposed rocky shore, rock pool, epiphytic on Cystophora torulosa (-46.65945, 168.84683), 20 August 2016, Nelson, W. A. & Twist, B. A. NZC5234 (Holoype: WELT A 033619).

Diagnosis:—Pale pink, dense tuft-like balls, 1.5–4 cm high and 1.5–3.5 cm wide. Dichotomous uniplanar basal and apical branching ( Fig. 4 ). Attachment via entangled stolons ( Fig. 5 ). Cylindrical branches with intergenicula (180) 190–330 (340) μm long and (70) 80–140 (160) μm wide. Genicula composed of single tier of elongated cells ( Figs 6, 7 ). Reproductive conceptacles forming at the tips of calcified segments. Tetrasporangial conceptacles broad and cylindrical, with 2–3 branchlets ( Figs 8, 9 ), spermatangial conceptacles long, narrow, and terminal, lacking branchlets ( Figs 10, 11 ), and carposporophytes are rounded and broad, 2–3 branchlets ( Figs 12, 13 ).

identify species.

collected in this study.

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Distribution and habitat:— Jania sphaeroramosa is found year round in pools in the low intertidal zone to the upper subtidal zone, typically on exposed rocky coastlines. It is epiphytic on a range of hosts, most commonly Cystophora spp. , Halopteris spp. and on other species of geniculate coralline algae, although specimens that are attached to other geniculate coralline algae can often appear to be epilithic. It has been confirmed by sequence and morphological data to occur in the North, South, Stewart, Chatham and Auckland Islands of New Zealand.

Etymology: —The specific epithet refers to the round and richly branched habit characteristic of this species.

Morphology: The terete three-dimensional growth form of this species, built up of multiple layers of dichotomous fronds, is highly characteristic, and often many thalli are present on a single host, particularly Cystophora spp. The thalli are attached to hosts by a complex intertwining system of stolons which are generally at 90 degrees to the main axis and up to tens of intergenicula in length. Thickened and rounded intergenicula occur at irregular intervals on the stolons. The ratio of intergenicula length to width was highly variable (1.36-3.86 L/W).

Distinguishing features: The intergenicula length and width of J. micrarthrodia reported in Womersley and Johansen (1996) are noted as shorter and wider (length: (70 –) 100 – 200 (– 250) μm and width: 120–200 (–250) μm) than the intergenicula measurements made for J. sphaeroramosa presented here (length: 190–330 μm and width: 80–140 μm). Additionally, a discoid holdfast base is recorded for J. micrarthrodia in Womersley and Johansen (1996), and this feature has not been identified in J. sphaeroramosa specimens examined in this study. Jania sphaeroramosa presented in this paper does not conform to the description for J. crassa J.V.Lamour. as shown in Woelkerling et al. (2015). This species is reported to be coarser, with intergenicula being 280–370 μm in diameter and 700–2200 μm in length, compared to measurements of J. sphaeroramosa recorded in this study.

Figures

FIGURE 3. Holotype of Jania sphaeroramosa Twist, J.E.Sutherl. & W.A.Nelson, sp. nov. (WELT A033619 / A+B). Scale bar = 1 cm.

FIGURE 4–13. Jania sphaeroramosa sp. nov. 4. View of the dichotomous branching and uniplanar arrangement (scale bar = 1 cm). 5. Entanglement of stolons around host for attachment (scale bar = 1 cm). 6. Intergeniculate and geniculate segmentation and branching (scale bar = 50 μm). 7. Single tier of elongated intergeniculate cells (scale bar = 20 μm). 8. Tetrasporangial conceptacles with 2–3 branchlets sometimes leading to other tetrasporangia (scale bar = 200 μm). 9. Tetrasporangial conceptacles showing tetraspores with zonate division (scale bar = 100 μm). 10. Terminal male conceptacles (scale bar = 100 μm). 11. Male conceptacles (scale bar = 50 μm). 12. Carposporophyte conceptacles with 2–3 branchlets (scale bar = 200 μm). 13. Carposporophytes showing carpospores (scale bar = 100 μm).