Rapid plastic responses to chronic hypoxia in the bearded fireworm, Hermodice carunculata (Annelida: Amphinomidae)
- PDF / 1,443,926 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 0 Downloads / 178 Views
ORIGINAL PAPER
Rapid plastic responses to chronic hypoxia in the bearded fireworm, Hermodice carunculata (Annelida: Amphinomidae) Candace J. Grimes1 · Paulo C. Paiva2 · Lene H. Petersen1 · Anja Schulze1 Received: 21 March 2020 / Accepted: 12 August 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Hypoxia is a widespread and increasing phenomenon in marine environments, including coral reefs. The bearded fireworm (Hermodice carunculata) is a large corallivorous amphinomid polychaete, with a high tolerance of environmental stress, including temperature, salinity, and dissolved oxygen (DO). Currently, little is known about the response of H. carunculata to chronic (≥ 18 h) hypoxia, although this knowledge is crucial to understand its impact on coral reef health under hypoxia scenarios. We tested the hypothesis that the number of branchial filaments (previously used as a diagnostic character for species identification) increases in response to chronic hypoxia. We subjected wild-caught fireworms to two levels of reduced DO (Mid: 4.5 ± 0.25 mg O2 L−1 and Low: 2.5 ± 0.25 mg O2 L−1) to explore their morphological and physiological responses to seven days of chronic hypoxia. Hypoxia exposure resulted in a higher number of branchial filaments (low = 57.2 ± 5.3, mid = 57.4 ± 6.1, and normal = 47.4 ± 11.2) after seven days. Fireworms exposed to hypoxia further reduced their rate of regeneration, but returned to normal regenerative rates after fifteen weeks under normoxic conditions. There was no difference in regeneration rates between low and mid DO groups. Our results demonstrate the importance of considering multiple physiological and morphological endpoints as well as phenotypic plasticity in species delimitations. Indeed, the results suggest that morphological variation can be indicative of environmental conditions.
Introduction Oxygen depletion, generally caused by increased nutrient loading, freshwater inflow, and water stratification, is an emergent stressor in the world’s oceans (Altieri and Gedan 2015; Nelson and Altieri 2019; Altieri and Diaz 2019). Responsible Editor: H.-O. Pörtner. Reviewed by N. Lucey and undisclosed experts. * Candace J. Grimes [email protected] Paulo C. Paiva [email protected] Lene H. Petersen [email protected] Anja Schulze [email protected] 1
Marine Biology Department, Texas A&M University at Galveston, Galveston, TX 77554, USA
Instituto de Biologia–Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
2
In a given habitat, oxygen depletion may occur intermittently or chronically (> 18 h) (Diaz and Rosenberg 1995). The effects of chronic hypoxia on vertebrates, specifically teleost fish, have been described and studied extensively (e.g. Richardson et al. 2001; Wu 2002; Pires et al. 2010; Bayer and Vaupel 2012), but fewer studies have focused on marine invertebrates [e.g. members of Thalassinidea (Astall et al. 1997), Crassostrea gigas (Thurnberg 1973; David et al. 2005); Orconectus limosus (Rafinesque 1817 Wren et al. 2008); Hal
Data Loading...
