Crassitegula bouchetii L.Le Gall & C.W.Schneid., 2025

Schneider, Craig W. & Gall, Line Le, 2025, Two new species of Crassitegula (Sebdeniaceae, Sebdeniales, Rhodophyta) extend the diversity and biogeographic range of the genus to the Caribbean and Mediterranean seas, European Journal of Taxonomy 976, pp. 194-207 : 201-202

Crassitegula bouchetii L.Le Gall & C.W.Schneid. sp. nov.

Registration: http://phycobank.org/105326

Fig. 2

Diagnosis

The new species is genetically distinct from all of the other known species in the genus ( Fig. 1 ), and has characteristics reminiscent of immature blades of the generitype, C. walsinghamii .

Etymology

The species is named for Prof. Emeritus Philippe Bouchet of the Muséum national d’Histoire naturelle, who initiated the expedition program “Our Planet Reviewed” and coordinated the 2012 karubenthos expedition to Guadeloupe, where these collections were made.

Type material

GUADELOUPE • Deep reef off Marina de Rivière Sens, Basse-Terre , Guadeloupe , West Indies , Caribbean Sea ; 15°58′59.988″ N, 61°43′5.016″ W; depth 28 m; 21 May 2012; L. Le Gall FRA1944; GenBank nos PQ213414 (COI-5P) , PQ213421 (LSU) ; holotype: PC [ PC0143905 ].

Description

Plants saxicolous, prostrate, dorsiventrally organized, firm and smoothly textured, vermilion-red (Graf 1x 2023); blades irregularly orbicular to ovate and up to 6.4 mm wide ( Fig. 2A ), attached by a short, thick, submarginal to more central holdfast ( Fig. 2A ); blades 350–380 µm thick with crenate margins, margins rounded in section; axes multiaxial, medulla loosely filamentous with long, thin, mostly anticlinal filaments 2–3 µm in diam., connected to inner cortex by regular network of stellate ganglia with spherical to rounded angular bodies 6–12 µm diam., each pit-connected to multiple radiating medullary filaments ( Fig. 2B–D ); cortex 3–4 layered with periclinally flattened larger inner cortical cells 9–15 µm diam., grading to smaller outer cortical cell layers ( Fig. 2B ), surface cells irregularly rounded to spherical and small, 3–6 µm in diam., loosely spaced, often with paired larger and smaller cells ( Fig. 2E ); tetrasporangia and gametangia unknown.

Distribution and habitat

Presently known only from a deep reef off Marina de Rivière Sens , Guadeloupe, in the Caribbean Sea.

Figures

Fig. 2. Crassitegula bouchetii L.Le Gall & C.W.Schneid. sp. nov., FRA1944 [PC0143905]. A. Holotype, a gathering of peltate specimens with ventral surfaces and single thick holdfasts (arrowheads) showing. B. Transverse section through blade and margin showing layers of cortical cells with inner margin of stellate ganglia.C–D. Stellate ganglial cell network under the inner cortex in surface view with opposite cortex pulled away. E. Surface view of outer cortex. Scale bars: A = 1 cm; B, D–E = 25 µm; C = 50 µm.

Fig. 1. Concatenated maximum likelihood tree inferred from combined COI-5P + LSU markers of members of the Sebdeniales Withall & G.W.Saunders (outgroup Rhodymeniales Nägeli). Numbers on branches show the bootstrap support calculated with ultrafast bootstrap (1000 replicates) in IQ-TREE. Scale = substitutions per site. Specimens newly sequenced for this study are shown in boldface type.