Agar from two coexisting species of Gracilaria (Gracilariaceae) from the Mexican Caribbean

• Published in: Ciencias marinas Vol. 29; no. 2; pp. 211 - 228
• Main Authors: Espinoza Avalos, J, Hernandez Garibay, E, Zertuche Gonzalez, JA, Meave del Castillo, MA
• Format: Journal Article
• Language: English; Spanish; Portuguese
• Published: Universidad Autónoma de Baja California, Instituto de Investigaciones Oceanológicas 01.06.2003
• Subjects: Gracilaria; Marine; Marine & Freshwater Biology; ASW, Mexico; reproductive phases; Yucatan Peninsula; agar; Península de Yucatán; Gracilaria spp; seasonal changes; cambios estacionales; fases reproductivas
• ISSN: 0185-3880

Gracilaria cornea and G. crassissima are species that coexist at Bajo Pepito in the Mexican Caribbean. Differences in agar properties from both species were determined for two reproductive categories: carposporic and undetermined, the latter composed of tetrasporophytes. Agar yield (AY), agar gel strength (GS), 3,6-anhydrogalactose content (AG) and sulfate content (S) of native and alkali- treated agar were determined for both reproductive categories. Significant differences in native and alkali-treated agar between the reproductive categories were recorded for AY, GS and S from G. cornea and G. crassissima, as well as for AG of native agar from the latter species. Results demonstrate that reproductive stage was not predominant over the other(S) in terms of having greater or lower values of agar properties. Lower AY and GS were found for G. cornea from the Caribbean side of the Yucatan Peninsula (this study), in comparison to agar values for the Mexico Gulf side of the Peninsula. Warmer and nutrient poorer waters on the Caribbean side could cause those differences. No patterns for GS or S was found when these two and other tropical species of Gracilariaceae were compared to temperate species. When plants of both reproductive categories were pooled together for each Gracilaria species, significant differences were found in all agar properties. Interspecific and intraspecific differences between and within species of Gracilariaceae have also been found for phenological events. Was suggested, the coexistence of G. cornea and G. crassissima by require different phenological responses for the environment at Bajo Pepito, which can be reflected in differences in the agar properties measured, both at the interspecific and intraspecific levels.