Pterocladiella caloglossoides (M.Howe) Santelices

Boo, Ga Hun, Calderon, Martha S. & Boo, Sung Min, 2017, A new marine alga, Pterocladiella andresii sp. nov. (Gelidiales, Rhodophyta) and its relationship to P. caloglossoides from Pacific South America, Phytotaxa 319 (2), pp. 139-148 : 143-144

Pterocladiella caloglossoides (M.Howe) Santelices ( Figs 10–18 )

Type: — PERU. Lima, Isla San Lorenzo (12°05’23” S, 77°13’26” W), dredged in 2.5 fathoms ; Coker 59 P. P. (holotype lost, Renfrew et al. 1989) .

Specimens observed: — PERU. Paita, Yacila (5°7’48” S, 81°10’09” W), in drift or on intertidal rocks, 14 February 2012, S. M. Boo ( CNU 024786 [tetrasporophyte], CNU 024818 [female gametophyte] in CNUK).

Plants forming turfs up to 0.8 cm tall, yellowish to light red, repent to erect, sometimes complanate throughout ( Figs 10, 11 ); prostrate stolons relatively terete to complanate, with peg-like haptera; erect branches arising in cluster of 2–5 branches on dorsal nodes of stolons where haptera arise, simple or rarely irregularly branched, linear or ribbon-shaped, 190–500 μm in width, approximately 100 μm thick; younger branches lanceolate or acuminate; surface cells in the apical region in very distinct oblique rows, irregularly arranged in the center of erect axes, 7–11 μm in diameter ( Fig. 12 ). Apical cells single, dome shaped.

Cortex consisting of 3–4 layers of pigmented cortical cells. Medulla containing large colorless cells in a single row, rarely two layers, with translucent rhizines around medullary cells ( Fig. 13 ).

Tetrasporangial sori arising on ultimate ligulate branches and branchlets, without sterile margins, approximately 280 μm in diameter ( Fig. 14 ); tetrasporangia 15–21 μm × 20–35 μm, arising from inner cortical cells, arranged in v-shaped rows, and cruciately divided ( Fig. 15 ).

Female plants bearing cystocarps at tips of main axes or branches, protruding on both sides, with a single ostiole ( Figs 16, 17 ); cystocarps with unilocular, ovoid cavity, approximately 220 μm wide and 95 μm thick, with a sterile margin, and producing chains of carposporangia ( Fig. 18 ). Rhizines well-developed on both inner sides of cystocarps. Male plants not observed.

Distribution and Habitat: —The type specimens were collected on shells, dredged in 2.5 fathoms at Isla San Lorenzo by Howe. Our specimens from Yacila, Peru occurred on articulated coralline algae in the drift and on small pebbles in the intertidal zone.

Identification using mitochondrial cox 1 and plastid rbc L sequences: —Six sequences were generated in the present study: two cox 1 and two rbc L from P. caloglossoides , and each of cox 1 and rbc L from P. andresii . Pterocladiella caloglossoides and P. andresii differed by 9.7% in cox 1 and 3.9 % in rbc L.

The topology of the ML and BI trees was largely congruent; for the concatenated dataset (rbc L + cox 1), the ML tree is shown ( Fig. 19 ). Topologies of the cox 1 and rbc L separately were similar to the concatenated phylogeny but with weaker statistical support ( Figs S1, S2 ). The concatenated tree ( Fig. 19 ) included 42 taxa (2,598 bp) and strongly supported the monophyly of the genus Pterocladiella (99% ML, 1.0 BPP). Pterocladiella caloglossoides from Peru was clearly separated from P. caloglossoides from Australia. Pterocladiella andresii was distinct from other species of Pterocladiella in trees of both individual and concatenated datasets ( Fig. 19 , Figs S1, S2 ). Pterocladiella andresii was sister to P. caloglossoides , and this group formed a clade with P. luxurians (Collins) G.H.Boo & K.A.Miller in Boo et al. (2016c: 35337) (100% ML, 1.0 BPP).

Figures

FIGURE 19. Maximum likelihood tree of concatenated (rbcL + cox1) dataset from Pterocladiella. The numbers above or below the nodes are RAxML bootstrap values and Bayesian posterior probabilities. Only bootstrap values ≥50% and Bayesian posterior probabilities ≥90 are shown in the tree.

FIGURES 10–18. Pterocladiella caloglossoides (Howe) Santelices. 10. Plants attached to articulated coralline alga (CNU024786). Scale bar = 2 mm. 11. Habit of plant showing irregular branching (CNU024786). Scale bar = 1 mm. 12. Irregularly arranged outermost cortical cells in center of erect axes. Scale bar = 10 μm. 13. Transverse section of erect branch showing outermost cortical cells (oc), inner cortical cells (ic), rhizines (rz) and medullary cells (mc). Scale bar = 20 μm. 14. Tetrasporangial sorus on spatulate branch with v-shaped arrangement of tetrasporangia (CNU024786). Scale bar = 100 μm. 15. Transverse section of tetrasporangial sorus showing tetrasporangia (arrowheads). Scale bar = 20 μm. 16. Habit of female plant with cystocarps (arrowhead) (CNU024818). Scale bar = 1 mm. 17. Side view of cystocarp showing swelling on both sides (arrowhead). Scale bar = 0.5 mm. 18. Transverse section of mature cystocarp showing carpospores (arrowheads). Scale bar = 20 μm.

FIGURES 1–9. Pterocladiella andresii G.H. Boo, M.S. Calderon & S.M. Boo, sp. nov. 1. Habit of a holotype specimen (CNU012838). Scale bar = 2 mm. 2. Habit of isotype specimen (CNU012838-1). Scale bar = 2 mm. 3. Habit of isotype specimen (CNU012838-2). Scale bar = 2 mm. 4. Apex of young branch showing apical cell (arrowhead) and surface cells arranged in arcuate pattern. Scale bar = 20 μm. 5. Irregularly arranged outermost cortical cells in surface view in center part. Scale bar = 20 μm. 6. Transverse section of erect branch showing outermost cortical cells (oc), inner cortical cells (ic), rhizines (rz) and medullary cells (mc). Scale bar = 20 μm. 7. Tetrasporangial sorus with irregularly arranged tetrasporangia (CNU012838-3). Scale bar = 100 μm. 8. Young tetrasporangial sorus with v-shaped tetrasporangial arrangement (CNU012838-3). Scale bar = 200 μm. 9. Transverse section of tetrasporangial sorus showing tetrasporangia (arrowheads). Scale bar = 50 μm.