Age and growth of Lithothamnion muelleri (Corallinales, Rhodophyta) in the southwestern Gulf of California, Mexico

Abstract

ResumenEl alga coralina no geniculada Lithothamnion muelleri Lenormand ex Rosanoff es comúnmente encontrada formando mantos de rodolitos en zonas someras expuestas al oleaje dentro del suroeste del Golfo de California. Esta especie tiene bandas de crecimiento a todo lo largo de las ramas principales del talo que sugieren un crecimiento periódico y que probablemente podrían ser utilizadas para determinar su tasa de crecimiento y edad. Como parte de la investigación que se está desarrollando sobre los mantos de rodolitos y su ecología, se desarrollaron observaciones sobre la naturaleza de esas bandas en la estructura de las plantas y en experimentos de crecimiento en campo y laboratorio. Se marcaron con alizarina plantas individuales de diferentes clases de talla en el campo y otro conjunto de plantas fue al laboratorio llevado para su análisis. La mitad de las plantas fueron muestreadas después de 6 meses y el resto recolectadas a los 12 meses. Los resultados muestran una tasa de crecimiento de 0.60 mm año -1 en el campo y 0.87 mm año -1 en el laboratorio. Los análisis estadísticos mostraron que no existen diferencias significativas entre las ramas de una planta, ni entre plantas de diferentes tamaños. El crecimiento fue estacional, con mayores tasas en invierno y primavera y menores en verano y otoño. Esto puede explicar la alternancia de bandas claras y obscuras (hasta 4) a lo largo de una rama principal. Las tasas de crecimiento sugieren que las plantas más grandes (p.ej. 15 cm de diámetro) podrían tener más de 100 años de antigüedad.Palabras clave: edad, crecimiento, Lithothamnion muelleri, rodolitos, Corallinales. AbstractThe nongeniculate coralline alga Lithothamnion muelleri Lenormand ex Rosanoff is commonly found as a free-living rhodolith in the wave-exposed shallow waters of the southwestern Gulf of California. This species has bands along the main branch axes suggesting that growth is periodic and that may be used to determine age and growth. As part of our ongoing research related to rhodoliths and their ecology, we have made observations on the nature of these bands based on their structure in entire plants and on field and laboratory growth experiments. Individual plants from different size classes were tagged, stained with alizarin and returned to the field, while another set was tested in the laboratory. Half of the plants were sampled after 6 months and the rest after 12 months. The data indicate that this species grew at a rate of 0.60 mm yr -1 in the field and 0.87 mm yr -1 in the laboratory. There were no significant differences among branches within a plant, or among plants of different size. Growth was seasonal, with high rates in winter and spring, and low rates in summer and fall. This may explain the observed alternating light-dark bands (up to 4) along branch axes. The growth rates suggest that larger plants (ca 15 cm diameter) may be over 100 years old.

Environmental factors controlling the distribution of rhodoliths: An integrated study based on seafloor sampling, ROV and side scan sonar data, offshore the W-Pontine Archipelago

“…In particular, L. corallioides and P. calcareum are included in annex V of the Habitats Directive. Rhodoliths and maerl preservation is particularly important also due to the slow growth rate of coralline red algae (Frantz et al, 2000;Blake and Maggs, 2003;Rivera et al, 2004;Schäfer et al, 2011), which makes them lowly resilient to environmental stress (Grall and Hall-Spencer, 2003;Wilson et al, 2004;Nelson, 2009).…”

Population biology of a long-lived rhodolith: the consequences of becoming old and large

“…Growth rates range from <1.0 mm yr −1 (reviewed in Foster 2001) to > 5.0 mm yr −1 (Steller et al 2007) depending on species and estimation technique. Direct field measurements (Adey & McKibbin 1970), changes in calcium carbonate weight (Potin et al 1990), 14 C dating (Littler et al 1991, Frantz et al 2000, Goldberg 2006), Mg:Ca ratios (Halfar et al 2000, Kamenos et al 2008, Alizarin Red staining (Blake & Maggs 2003, Rivera et al 2004, Steller et al 2007, Amado-Filho et al 2012, or a combination of these techniques (Darrenougue et al 2013) have all been used to determine growth rates and/or age. Growth is typically more rapid in summer than in winter (Adey & McKibbin 1970, Potin et al 1990, Steller et al 2007, with one report of faster growth in winter (Rivera et al 2004).…”

“…Direct field measurements (Adey & McKibbin 1970), changes in calcium carbonate weight (Potin et al 1990), 14 C dating (Littler et al 1991, Frantz et al 2000, Goldberg 2006), Mg:Ca ratios (Halfar et al 2000, Kamenos et al 2008, Alizarin Red staining (Blake & Maggs 2003, Rivera et al 2004, Steller et al 2007, Amado-Filho et al 2012, or a combination of these techniques (Darrenougue et al 2013) have all been used to determine growth rates and/or age. Growth is typically more rapid in summer than in winter (Adey & McKibbin 1970, Potin et al 1990, Steller et al 2007, with one report of faster growth in winter (Rivera et al 2004). Although growth estimates are variable, all have concluded that rhodoliths are slow-growing and some may live for >100 yr (Frantz et al 2000, Rivera et al 2004.…”

The Mediterranean bioconstructor Lithophyllum stictiforme shows adaptability to future warming

“…For the setup of both experiments, healthy L. stictiforme (about 8 cm in diameter) with no signs of damage or bleaching were carefully collected (detaching their basal parts using hammer and chisel) by SCUBA diving (Figure 3A) and transported in insulated aquaria to the laboratory within one hour, where they were cleaned from epiphytes and rinsed with new seawater. Afterwards, they were placed in aquaria with oxygenators, kept at the temperature of their origin environment and stained using Alizarine-Red stain (Sigma-Aldrich, Steinheim, Germany) 0.25 g•l-1 for 24 h (Blake and Maggs, 2003;Rivera et al, 2004). The stained L. stictiforme thalli were transported to the receiving sites and glued with a twocomponent epoxy underwater filler (Sub Coat Veneziani) on granite tiles which were attached on horizontal substrates in the field (Figure 3A).…”