Corynecladia mediterranea Metti & Furnari & Serio 2024, sp. nov.
Creators: name: Metti, Yola
name: Furnari, Giovanni
name: Serio, Donatella
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Rhodophyta
Florideophyceae
Ceramiales
Rhodomelaceae
Corynecladia
Corynecladia mediterranea

description: Corynecladia mediterranea sp. nov.
(Figs 6-8)
Plants red-yellowish in colour, soft in texture, forming tufts up to 8 cm high; thalli terete up to 2 mm in diameter, arising from a discoid holdfast with secondary stoloniferous branches; branching irregularly alternate, usually with 2(3) orders of branches; ultimate branchlets are cylindrical-clavate; four periaxial cells per vegetative axial segment. Secondary pit-connections between cortical cells localized in middle to inner part of the cells. Cortical cells with one corps en cerise. No lenticular thickenings. Tetrasporangia in parallel arrangement cut-off abaxially from the third and fourth periaxial cells. It differs from other species of Corynecladia in showing neither secondary cortication nor starch grains in medullary cells and from genera Laurencia and Laurenciella in the occurrence of deep secondary pit connections between cortical cells. It differs from the related C. millarii mainly in different molecular sequences.
TYPE MATERIAL. — Italy • Sicily, Trapani, San Vito Lo Capo, Golfo di Monte Cofano; 38°06’21”N, 12°41’36”E; epilithic; 0.5 m depth; 9.VII.2017; D. Serio; holotype (tetrasporophyte): CAT [CAT 2724]; GenBank: OQ738971 • ibid.; Porto Palo di Capo Passero; 36°39’03.8”N, 15°04’37.4”E; epilithic; 0.2 m depth; 8.V.2021; D. Serio; paratype (tetrasporophyte): CAT [CAT 2726]; GenBank: OQ738950, OQ738951.
TYPE LOCALITY. — Italy, Sicily, Trapani, San Vito Lo Capo, Golfo di Monte Cofano.
ETYMOLOGY. — The specific epithet indicates the Sea in which the species was found.
DISTRIBUTION. — Type locality, Golfo di Monte Cofano (Trapani, Sicily); Porto Palo di Capo Passero (Syracuse, Sicily); and probably more widely distributed.
HABITAT. — Plants epilithic in upper subtidal up to 1 m depth.
DESCRIPTION
Plants epilithic, soft, red yellowish, up to 8 cm high, terete throughout, attached to substrate by a discoid holdfast with stolon-like branches and smaller discoid holdfasts (Fig. 6A, B). Erect axes, 1-2 mm in diameter in the middle portion of the thallus, irregularly alternate, usually with 2(-3) orders of branches. Epidermal cells with slight projection near the apex (Fig. 7A). One corp en cerise per cortical cells (Fig. 7B). Cortical cells showing thin secondary pit-connections. In longitudinal section they appeared localized in the middle to inner part of the cells (Fig. 8A). In transverse section, cortical cells quadratic to rectangular, neither radially elongated nor arranged as a palisade, measuring 25-30 ×30-35 µm in the middle portions of the plant (Fig. 8B). Medullary cells rounded, 40-50×35-45 µm in the middle portions of the plant, larger toward the center of the axes. Walls of medullary cells without lenticular thickenings (Fig. 8B). Each vegetative axial segment cuts off four periaxial cells (Fig. 8D). Tetrasporangial initials cut off abaxially from the third and fourth periaxial cells (Fig. 8D). No additional tetrasporangial periaxial cells produced. Mature tetrasporangia tetrahedrally divided, 90-100 µm in diameter. Tetrasporangia forming a parallel arrangement along the axis of the stichidium (Fig. 8C). Gametangia unknown.
description: Published as part of Metti, Yola, Furnari, Giovanni & Serio, Donatella, 2024, Molecular analyses reveal the presence of Corynecladia J. Agardh (Rhodophyta, Rhodomelaceae) in the Mediterranean Sea with two new species, C. millarii sp. nov. and C. mediterranea sp. nov., pp. 11-30 in Cryptogamie, Algologie 20 (2) on pages 15-16, DOI: 10.5252/cryptogamie-algologie2024v45a2, http://zenodo.org/record/10698178