Diversity and distribution of species of the planktonic dinoflagellate genus Alexandrium (Dinophyta) from the tropical and subtropical Mexican Pacific Ocean Author Hernández-Becerril, David U. Author Pichardo-Velarde, Jorge G. Author Alonso-Rodríguez, Rosalba Author Maciel-Baltazar, Ebodio Author Morquecho, Lourdes Author Esqueda-Lara, Karina Author Barón-Campis, Sofía A. Author Quiroz-González, Nataly text Botanica Marina 2023 Warsaw, Poland 2023-11-06 66 6 539 557 http://dx.doi.org/10.1515/bot-2023-0037 journal article 10.1515/bot-2023-0037 1437-4323 11000291 3.2 Molecular phylogeny of Mexican Pacific Alexandrium species Only sequences obtained from strains housed in CODIMAR were considered for the phylogenetic analysis: A. affine (AAMV-1, 2, 3, 4, from BahÍa Mazatlán), A . margalefii (AMCQ-1 from BahÍa Concepción), A . tamiyavanichii (AYPV-1, from BahÍa de La Paz ) and A . tropicale (ATUV-1, from Jalisco ) ( Figure 1 , Table 2). Seven sequences were obtained for the D1-D2 LSU rDNA, and six sequences for the ITS rDNA (Table 2). Both topologies of the trees following the Maximum likelihood and Bayesian inference were generally consistent, thus, only the maximum likelihood trees are shown ( Figures 70 and 71 ). The trees showed that A. affine , A. margalefii , A. tropicale and A. tamiyavanichii strains from the Mexican tropical Pacific clustered together with the corresponding species reported from various marine regions worldwide, retrieved from the NCBI , with high and moderate values of bootstrap and Bayesian posterior probabilities for LSU ( Figure 70 ) and for A. affine , A. margalefii and A. tropicale for ITS ( Figure 71 ). In the LSU rDNA tree, A. tamiyavanichii clustered close to the presumably closely related species A. cohorticula ( Figure 70 ), whereas the ITS tree showed A. tropicale close to A. fraterculus , but with moderate support values ( Figure 71 ). The Jukes-Cantor genetic distance matrix calculated based on LSU and ITS rDNA showed the values of intraspecific distance of A. affine , A. margalefii , A. tamiyavanichii and A. tropicale compared with strains of these species from other regions of the world, and with other species of Table Z: General information and GenBank accession numbers for Alexandrium strains from the Mexican Pacific studied in this work.

Species	CODIMAR	GenBank accession number		Collection	Isolation	Culture media and	Locality	Coordinates
code	LSU rDNA (D¹/DZ)	ITS rDNA (ITS¹/ S.BS/ITSZ)	date	date	incubation temperature
A. a ffi ne	AAMV-1	OQ676503	OQ676843	16/06/13	17/06/13	f/2 + Se, 20 °C	BAMAZ	23°09′48.30″N 106°
26′15.90″W
AAMV-2	OQ676504	OQ676844	24/02/20	03/03/20	GSe, 20 °C	23°11′2.7″N 106°
25′34.5″W
AAMV-3	OQ676505	OQ676845	24/02/20	03/03/20	GSe, 20 °C	23°11′2.7″N 106°
25′34.5″W
AAMV-4	OQ676506	OQ676846	24/02/20	03/03/20	GSe, 20 °C	23°11′2.7″N 106°
25′34.5″W
A. margale fi i	AMCQ-1	OQ676523	OQ676882	15/04/00	17/04/00	GSe, 20 °C	BACO	26°35′46.30″N 111°
44′20.66″W
A. tamiyavanichii	AYPV-1	OQ676527	–	09/2003	09/2003	GSe, 20 °C	BAPAZ	24°17′12.66″N 110°
20′31.92″W
A. tropicale	ATUV-1	OQ676586	OQ676883	20/08/18	21/08/18	GSe, 25 °C	BACUA	19°13′46.00" N
104°43′51.00″W

BAMAZ , Bahía de Mazatlán, Sinaloa ; BACO , Bahía Concepción, Baja California Sur ; BAPAZ , Bahía de La Paz , Baja California Sur ; BACUA , Bahía de Cuastecomates, Jalisco ; –, no information.