Seagrass Halodule wrightii as a new habitat for the amphioxus Branchiostoma californiense (Cephalochordata, Branchiostomidae) in the southern Gulf of California, Mexico

Abstract

The first record of the amphioxus Branchiostoma californiense on seagrass patches of Halodule wrightii in the Gulf of California is reported. Sixty individuals (19 males, 18 females, and 23 undifferentiated) were collected in May 2017 at Bahía Balandra, Gulf of California, from subtidal seagrass patches at a depth of 0.5 m at low tide. The length and weight ranged from 15.88–28.44 mm and from 0.01–0.11 g for females and 11.7–27.9 mm and 0.01–0.09 g for males, respectively. The minimum size of sexually mature individuals was 11.70 mm for males and 15.88 mm for females; 62% of the specimens were sexually mature. Analysis of the total length-weight relationship suggested an allometric growth pattern among females, males and undifferentiated individuals, whereas an analysis of the entire sample suggested an isometric growth pattern. Typical and additional morphological characters were used to identify the amphioxi. High morphological variability between individuals was found, suggesting the presence of several morphotypes. Branchiostoma californiense had been previously reported as exclusively associated with bare sandy areas, but our study shows that this species can also be found in seagrass patches, using them as breeding and feeding grounds. Thus, seagrass patches are evidenced as suitable habitats for amphioxus.

Updating and validating seagrass ecosystem knowledge in the gulf of California: a comprehensive review

“…However, since 2010, new studies have emerged that focus on the seasonal characteristics of H. wrightii, including evaluations of the abundance and morphology of its shoots, as well as biomass quantification (Santamarıá-Gallegos, 2016;Garcıá-Trasviña, 2017). Notably, Campos-Davila et al (2019) and Peŕez-Estrada et al (2021, 2023 have provided descriptions of the species' phenology, physiological traits, and fauna associated with H. wrightii meadows.…”

Molecular taxonomy confirms that the northeastern Atlantic and Mediterranean Sea harbor a single lancelet, Branchiostoma lanceolatum (Pallas, 1774) (Cephalochordata: Leptocardii: Branchiostomatidae)

“…Several species were newly described, or their taxonomy has been clarified only recently [2,29,30], and species misidentification or cryptic diversity have been found using molecular approaches or integrative taxonomy [14,[31][32][33][34][35][36]. Moreover, new records of lancelet larvae or adults improved our assessment of species-specific geographical distribution and ecological traits at a range of scales [37][38][39][40][41][42][43][44][45][46].…”

New records of Branchiostoma californiense (Amphioxiformes: Branchiostomatidae) in El Salvador, Central America

“…The presence of Branchiostoma californiense Andrews 1893 in the eastern Pacific has been documented in different marine areas of Mexico (Campos-Dávila et al, 2019;Galván-Villa et al, 2017;Velázquez-Velázquez, 2021). Also, its occurrence was documented in Nicaragua (Poss & Boschung, 1996) and Costa Rica (Vargas & Dean, 2010).…”