Northern Star Coral (Astrangia poculata) Populations from the New Jersey Coast.

Abstract- This project investigated the distribution and molecular evolution of the Northern Star coral (Astrangia poculata) on artificial reefs and shipwrecks in the local coastal ocean. This region consists primarily of gently sloping sandy plains without natural hard structure habitat. Unlike most corals which live in tropical to sub-tropical waters above 20 C and cannot tolerate high turbidity, the Northern Star Coral is found from the sub-tropics to the temperate zone. Colonies can be encrusting, massive or branching. Coral colonies, containing at least 5-10 corallites per sample were collected by scuba diver from seven sites offshore of Atlantic City, NJ at depths from 20-30 m. Approximately 20 mg of tissue from individual polyps was used to extract genomic DNA. The small subunit (18s) ribosomal RNA gene was amplified from coral genomic DNA by the polymerase chain reaction (PCR) using eukaryotic universal primers. PCR products were cloned and plasmid preparations were DNA sequenced. This DNA sequence information was aligned to determine the genetic relationship of the individuals using a reference A. poculata sequence from Genbank. Genetic variation between the local sites was found to be very low but will serve as a baseline for collections over a wider geographic range.

Peter F. Straub and Tara L. LukeSchool of Natural Sciences & Math, Richard Stockton College, Pomona, NJ 08240

Methods• Corals heads were collected from 7 sites off NJ coast ( Fig. 1.) by scuba diver (Figure 2.). Figure 3 is an in situ coral head.• DNA was extracted from individual polyps and amplified by PCR using universal primers for the small subunit (18S)of ribosomal RNA (Figure 4.)•PCR products were cloned into pGemT (Promega) and DNA sequenced using on a Beckman CEQ genetic analyzer (Fig. 5).•DNA sequences were BLAST (NCBI) searched for identity•Sequences were aligned in Vector nTI (Invitrogen) and analyzed using PAUP. Acknowledgements: Support for this project came from the School of Natural Sciences

& Math, Richard Stockton College, and NSF DBI-#0619611. Photo credit for Fig 2. David Roche. Thanks to contribution of students of BIOL 2175, BIOL 4215 and BIOL 4211.

l

Fig. 1. Study sites offshore of Atlantic City, NJ.

Results: DNA extracted from corals produced a ca. 550 bp PCR product. After cloning of the PCR product and DNA sequencing, both BLAST search and nucleotide alignment indicated that all of the samples collected belong to a Scleractinian coral, most likely Astrangia poculata. All sequences match the Northern Star Coral with no more than one or two base pair differences per sequence in this region, with very little variability either between or among populations (Figure. 6). The inferred Maximum Parsimony tree constructed in PAUP includes both our collected coral sequences and available sequences from a number of related coral species within the Subclass: Hexacorallia; Order: Scleractinia (Figure. 7).

Introduction: A prominent members of the invertebrate assemblage colonizing shipwrecks and artificial reefs in the coastal waters offshore of New Jersey is the Northern Star coral (Astrangia poculata) synonyms A. danae and A. astreiformis, Phylum Cnidaria; Class Anthozoa. This region is generally devoid of natural hard structure habitat, consisting primarily of gently sloping sandy plains. Most scleractinian corals, subclass Hexacorallia; Order Scleractinia, live in tropical to sub-tropical waters above 20º C and cannot tolerate high turbidity. However, an exception is the Northern Star Coral which is found from the sub-tropics to the temperate zone on the Northwest Atlantic coast. The purpose of this study was to look at genetic differentiation of locally collected populations of star coral in relation to their wide ecological amplitude and their habit of colonizing a substrate that is extremely patchy.

Coral Collection sites7 sites, 15 dives

NJ

Figure 2. Representative coral collection site, wreck of the Almirante at 20 m.

Figure 3 In situ coral head Figure 4. Coral PCR products

500 bp

Figure 5. Coral DNA sequence from output Beckman CEQ

Fig 6. Alignment of 24 NJ artificial Reef samples with 1 full length Astrangia poculata (MA) and 9 other Scleractinian coral species (only part of alignment shown).

Jet Trader 9-1

Sea Girt 2-3

Glory 1-1

Astrangia poculataPhyllangia moucheziiFungia scutariaAlmirante 24-2

Almirante 24-1

Almirante 23-2

Almirante 21-2

Car Float 22-1

Car Float 20-2Lemuel Burrows 21-2

Lemuel Burrows 21-1

Lemuel Burrows 20-2

Jet Trader 8-3

Jet Trader 8-2

Jet Trader 20-1

John Marvin 5-3

John Marvin 5-1

John Marvin 1-1

Sea Girt 2-4

Sea Girt 2-1

Glory-20-2

Glory 2-1Corynactis californicaCorynactis sp.Enalopsammia rostrataTubastraea coccineaPavona variansCirrhipathes lutkeniMo

Figure 7. Maximum Parsimony analysis of 554 base pairs of the 18S rRNA gene from collected samples, as well as several related coral sequences

Conclusion- the corals collected do in fact appear to be Astrangia poculata by both morphological and DNA analysis. The local population showed little genetic variation at the sequenced region of the small subunit (18S) ribosomal gene. In the future, this study will serve as a baseline for further comparison of more geographically distant populations of star coral. Continued study may benefit from identification of a more variable region of the small subunit gene.