High species richness of epiphytic Mastogloia (Mastogloiales: Bacillariophyceae) on Thalassia testudinum along the coast of Campeche, southern Gulf of Mexico

Abstract

Revista Mexicana de Biodiversidad 91 (2020): e912976 Taxonomy and systematics High species richness of epiphytic Mastogloia (Mastogloiales: Bacillariophyceae) on Thalassia testudinum along the coast of Campeche, southern Gulf of Mexico Alta riqueza de especies de Mastogloia (Mastogloiales: Bacillariophyceae) epifitas de Thalassia testudinum en la costa de Campeche, sur del golfo de México AbstractDiatoms of the genus Mastogloia are naviculoid forms that are generally easy to discriminate due to the presence of marginal chambers known as partecta. They exhibit a wide marine distribution, and are basically benthic forms usually conspicuous in epiphytic and epipelic diatom assemblages. Our objective was to identify species of Mastogloia epiphytic on Thalassia testudinum blades from the southern Gulf of Mexico region. Blades of T. testudinum were collected off the coast of Campeche State, Mexico; the epiphytic diatoms were scrapped off, cleaned and mounted on permanent slides for identification under light microscopy. A total of 76 Mastogloia taxa were recorded. This is the highest number of Mastogloia taxa recorded for Mexican coasts. Seven taxa had not been observed for the region: Mastogloia angusta, M. belaensis, M. depressa, M. ovalis, M. pseudolacrimata, M. regula, and M. urveae. Likewise, 20 Mastogloia species are new records for the Gulf of Mexico, while 15 are new records for Mexican coasts overall. This study confirms that Mastogloia species are mostly distributed in tropical and subtropical habitats, and shows that much floristics and formal taxonomy are required on benthic diatoms from different types of substrata for Mexican littorals.

Additions to the Mastogloia (Bacillariophyceae: Mastogloiales) of the Revillagigedo Archipelago, Mexico

“…Elsewhere, the epilithic and epiphytic Mastogloia identified at the Adriatic Sea by Hafner et al (2018) reached 46 taxa using 25 samples gathered for 15 months. Moreover, although the total number of Mastogloia taxa recorded until now for the Revillagigedo Archipelago is closer to the one reported (71) for the southern Gulf of Mexico (Siqueiros-Beltrones et al, 2020), the latter also…”

“…Thus, although the Revillagigedo Archipelago is located within a transitional zone influenced by the California Current (Aguirre-Muñoz et al, 2015), the tropical component of the archipelago region seems to be a major factor enhancing the species diversity of epiphytic diatoms (Siqueiros-Beltrones et al, 2019). In particular, the Mastogloia species that currently comprise the higher number of species recorded for the archipelago (28 taxa) were here expected to at least approximate the number of species recorded recently for the southern Gulf of Mexico (Siqueiros-Beltrones et al, 2020).…”

“…The Mastogloia taxa were identified at 1,000× under an Olympus CH-2 (Olympus, Japan) compound microscope using clear field illumination, following Foged (1975Foged ( , 1978Foged ( , 1984, Hein et al (2008), Hustedt (1959), Lobban et al (2012), Loir and Novarino (2013), Moreno et al (1996), Peragallo and Peragallo (1908), Schmidt et al (1959), Siqueiros-Beltrones et al (2017, 2019, 2020, Stidolph et al (2012), Witkowski et al (2000). Taxonomic names were updated according to Guiry and Guiry (2021).…”

“…The genus Mastogloia is frequently the most diverse within benthic marine assemblages from warm seas (Hafner et al, 2018;Siqueiros-Beltrones et al, 2020. Currently, 271 species are accepted out of 420 taxa proposed worldwide (Guiry & Guiry, 2021).…”

“…The above accounts set a reference as to the expected diversity in any given area for species of the genus Mastogloia, particularly within tropical regions. However, they also show that much floristics and formal taxonomy are required on benthic diatoms from different types of substrata for Mexican littorals (Siqueiros-Beltrones et al, 2020). It thus seemed imperative to continue surveying the area in order to gather a precise reference on the diversity of Mastogloia taxa.…”