Guided by the northern star coral: a research synthesis and roadmap for Astrangia poculata

Abstract

The northern star coral, Astrangia poculata, is a temperate, facultatively symbiotic, scleractinian coral spanning the coastal western Atlantic. This calcifying species is mixotrophic with a broad geographical range, and therefore has high utility in addressing questions related to community ecology, symbiosis, population genetics, biomineralization and resilience to environmental perturbations. Here, we review the current A. poculata peer-reviewed literature, which is primarily found in six focal areas: geographic range, habitat and ecology, symbiosis, life history, microbiome and genomics and transcriptomics. A cross-cutting theme of these studies emerges as the value of an experimental system that is facultatively symbiotic. Yet, the historic overgeneralization of symbiotic versus 'aposymbiotic' A. poculata has constrained the interpretation of the basic biology and generalizability of conclusions. Emergent from our review, and timely with respect to climate change, is the value that A. poculata brings as an experimental system with the potential to test questions on range adaptability and environmental resilience. We identify future avenues of research for A. poculata studies that include integration of population genetics with organismal-molecular-cellular biology across the geographical range, while leveraging the power of the facultative symbiosis context.

Keywords: Astrangia poculata; coral; life history; symbiosis.

Figure 1.

(a) Symbiotic and (b) aposymbiotic Astrangia poculata colonies. (c) Close-up of an aposymbiotic A. poculata polyp. Scale bar in (a–c) represents 1 mm. (d) Ocean Biodiversity Information System (OBIS) and (e) Global Biodiversity Information Facility (GBIF) data on A. poculata distribution in the western Atlantic Ocean. Photos by Chloé Gilligan and Hollie Putnam.

Figure 2.

(a) Frequency of published Astrangia poculata literature over time. Publication numbers reflect peer-reviewed research articles; only publications prior to January 2025 are included. Dotted lines indicate important dates in A. poculata history. The name of the species changed from Astrangia danae to A. poculata in 1988 [1]. Astrangia poculata became the Rhode Island State Coral in 2021. (b) Percentages of the primary focal areas from published A. poculata literature. (c) Percentages of locations where A. poculata was studied.

Figure 3.

Outstanding key questions and suggested approaches to Astrangia poculata research. Coral silhouette from https://github.com/sPuntinG/Coral_stuff/tree/main.