Nisada stipitata Gold-Morgan, González-Resendiz, León-Tejera et Montejano, 2015

Gold-Morgan, Michele, González-Resendiz, Laura, León-Tejera, Hilda & Montejano, Gustavo, 2015, Description of coccoid cyanoprokaryote Nisada stipitata morphogen. et sp. nov. from the supralittoral zone in the tropical Mexican Pacific, Phytotaxa 220 (3), pp. 268-276 : 270

publication ID	https://doi.org/ 10.11646/phytotaxa.220.3.5
DOI	https://doi.org/10.5281/zenodo.13634874
persistent identifier	https://treatment.plazi.org/id/03F88784-D344-F64E-8F9C-FD7EFD56F8C7
treatment provided by	Felipe
scientific name	Nisada stipitata Gold-Morgan, González-Resendiz, León-Tejera et Montejano
status	sp. nov.

Treatment

Nisada stipitata Gold-Morgan, González-Resendiz, León-Tejera et Montejano , sp. nov. ( Figs. 2–6 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 )

Epilithic colonies of up to 5 mm in height. Biofilm formed by a colony of parallel, erect, short pseudofilaments of a maximum of three cells. From top view, colonies seen as composed of black round or oval cells which are pseudofilament apices: single (morph 1 in Figs. 2G and H View FIGURE 2 ) or in pairs (morph 2 in Figs. 2E and G View FIGURE 2 ). In lateral view, pseudofilaments with three types of mucilaginous structures visible: pad, stipe and cup, as cited in the generic description. Pseudofilaments enveloped by individual grayish-black, thin, firm or slightly diffluent sheaths ( Fig. 2I View FIGURE 2 ). Stipe with rigid mucilage, straight, conical or an inverted cone, with alternating horizontal dark and light stripes or bands; top of stipe with a black, cup- or bullhorn-shaped mucilaginous structure ( Figs. 2I, G View FIGURE 2 ; 3C View FIGURE 3 ; 4B, C View FIGURE 4 ). Cell content smooth, without granules, colorless or with an irregular brownish pattern ( Figs. 2I, K View FIGURE 2 ; 3A, E View FIGURE 3 ). Cell shape diverse: spherical, hemispherical, quadrate, clavate, ovate, obovate, elongate or an inverted cone ( Figs. 2L, M View FIGURE 2 ; 3E, F View FIGURE 3 ). Reproductive cells formed by binary fission. In morph 1, one or two daughter cells are released at a time; in morph 2, the two reproductive upper cells are released at a time. Dimensions: morph 1: pseudofilaments up to 7 μm (length); basal cells 0.5–3.0 × 1.0–2.5 μm (l × w); daughter cells 1.5–3.0 × 1.0–2.5 μm (l × w); in top view cells 1.0–2.5 μm (diameter). Morph 2: pseudofilaments up to 6 μm (length); basal cell 2.0–2.5 × 2.0 μm (l × w); daughter cells 3.0 × 1.5–2.0 μm (l × w); in top view 3.0 μm (diameter).

Type:— MEXICO. Oaxaca: San Agustín, insolated plateau of granitic cliff 7 m a.s.l., off marine tropical shore not exposed directly to wave shock, but only receiving intermittent spray, 15° 41’ 17.41” N, 96° 14’ 15.28” W, González-Resendiz & León-Tejera, 02-12- 2010 (C59, C61), 03-10-2012 (C701) (holotype FCME! C59, isotypes FCME!, C61, C701).

Etymology:—from Latin stipitata =‘stipitate’.

Observations: —The basic pseudofilament morphology in Nisada has many variants due to the way the cup and stipe develop and to the growth process of the pseudofilament. The cup begins as a narrow horizontal band which increases in width and each ‘horn’ seems to grow upwards ( Figs. 2I, K View FIGURE 2 ) until the two join. Different stages of this apparently upwards growth can be seen in lateral view as longer or shorter horns.

Pseudofilament heteropolarity in N. stipitata is expressed shortly after a cell enters in direct contact with a substrate, as in other heteropolar coccoid species, but also after every division of a non basal cell it produces a cup and stipe, or at least a cup, before being released. Even when the division of the first daughter cell occurs lengthwise, there is a cup and stipe between the basal mother cell and the two daughter cells. This ‘stronger version’ of heteropolarity of N. stipitata is associated with the basal part of each cell, whether in contact with an external substrate or another cell of its pseudofilament.

Nisada stipitata is very stable regarding the number of cells of the pseudofilament and the presence of its differentiated mucilaginous features; but it is also morphologically quite diverse. Three factors contribute to its variability, aside from that due to the development of the cup-stipe: 1) cell growth in different length/ width proportions, between and within pseudofilaments; 2) cell size reached before division or release; and 3) the possibility of two alternative planes of division of the first daughter cells.