Identification: Lateral line interrupted (in two parts), the anterior part high on the body and ending at the last soft ray of the dorsal fin, the posterior part midlateral on caudal peduncle. Distinctive black spot on anterior portion of the dorsal fin. Head, pelvic fins, and anterior portion of the body violet, posterior half of the body yellow (see photo, above). Two narrow yellow stripes on the head. Pelvic rays elongate, reaching well beyond the origin of the anal fin. Dorsal fin XI-XIII (9-11); anal fin III (10). Pectoral fin soft rays 14-17. From Böhlke and Randall (1963), Randall (1996) and Mooi and Gill (2002).
Similar species: Juvenile Spanish hogfish (Bodianus pulchellus) lacks the dark dorsal spot and diagonal separation of body colors. Heliotrope basslet (Gramma klayi) lacks the dorsal spot and has a pink to rose-colored forebody (not violet, as seen in fairy basslet).
No sexual dimorphism, except for size (see Asoh and Shapiro 1997).
Native Range: Bahamas, Mexico (Quintana Roo), Belize, Honduras, Colombia, Venezuela, Greater Antilles (Cuba, Haiti, Dominican Republic, Jamaica, Grand Cayman), and Lesser Antilles (Böhlke and Randall 1963; Mooi and Gill 2002).
Often erroneously reported from Bermuda (see Smith-Vaniz et al. 1999).
† Populations may not be currently present.
Ecology: Basslets (Grammatidae) are small, colorful fishes generally associated with coral reefs. The fairy basslet generally occurs in groups, and may hang upside-down under ledges. It has been recorded from depths to 65 m (Mooi and Gill 2002). The species preferentially occupies high vertical relief within the general reef areas occupied (Freeman and Alevizon 1983). Individual fish (both males and females) hover close to the substratum and defend a small area against intra- and inter-specific intruders (Freeman and Alevizon 1983). Fish generally occupy the same feeding sites for many months (Asoh 1996). Fairy basslet groups live in a social structure consisting of dominance hierarchies arranged by size, with the largest fish at each coral head being the dominant one (Freeman and Alevizon 1983). The diet of the fairy basslet consists primarily of free-living planktonic crustaceans, but the species will also eat parasitic forms (ectoparasites picked from the bodies of other fishes; Böhlke and Randall 1963).
In the Caribbean, the species has been used as a model to understand the effects of interactions between size classes and the effects of density dependence on juvenile recruitment and mortality (Webster and Hixon 2000; Webster 2003, 2004). These studies showed that the fairy basslet occupies the undersides of open reef ledges where it lives in dominance hierarchies maintained by aggression between size classes such that larger fish occupy prime plankton-feeding positions closer to the outer edge of the ledge (Webster and Hixon 2000). In an experimental manipulation, Webster (2004) found that juveniles transplanted to reefs with adults were more likely to suffer mortality than juveniles transplanted to reefs with no or few adults. This was because in the presence of adults, juveniles tended to feed at the back of aggregations, where feeding rates were generally lower and predators were more abundant. Additionally, predators tended to aggregate and spend more time in regions where densities of fairy basslets were high (Webster 2003).
Mating and reproduction have also been examined in detail for the fairy basslet. Individuals are initially bisexual in nature, then differentiate into either functional males or females (Asoh and Shapiro 1997). After differentiation has occurred, sex allocation is static (i.e., the species is a gonochore; Asoh and Shapiro 1997). The smallest sexually mature males and females were 32.8 and 25.3 mm total length (TL), respectively (Asoh and Shapiro 1997). In general, males were larger than females (Asoh and Shapiro 1997).
Reproduction occurs at dawn from February to June in Puerto Rico (Asoh 1996). Demersal eggs are produced in nests (small holes and crevices in the substratum) that are tended by the male parents (Asoh and Yoshikawa 1996). Aggregations of fairy basslets generally consist of one or two males, several females and some smaller males and juveniles (Asoh 1996). Membership in these aggregations was remarkably stable (Asoh 1996). Mating is polygynous with a one-male—multi-female group or promiscuous within a multi-male—multi-female group (Asoh 1996). Male parents tend the nests by chasing other species from the nest, constructing algal mats at the nest entrance, carrying pieces of algae into the nest interior and removing silt from the inside of the nest (Asoh and Yoshikawa 1996). Eggs hatch in about 10-11 days at 23 to 27 ºC; newly hatched larvae had pigmented eyes, well-developed jaws, a small amount of yolk, and were 2.9-3.8 mm TL (Asoh and Yoshikawa 1996).
References: (click for full references)
Asoh, K. 1996. Reproductive behavior and mating system of the fairy basslet, Gramma loreto
. Copeia 1996: 1037-1043.
Asoh, K. and D. Y. Shapiro. 1997. Bisexual juvenile gonad and gonochorism in the fairy basslet. Copeia 1997: 22-31.
Asoh, K. and T. Yoshikawa. 1996. Nesting behavior, male parental care, and embryonic development in the fairy basslet, Gramma loreto. Copeia 1996: 1-8.
Böhlke, J. E. and J. E. Randall. 1963. The fishes of the western atlantic serranoid genus Gramma. Proceedings of the Academy of Natural Sciences, Philadelphia 115: 33-52.
Courtenay, W. 1995. Marine fish introductions in southeast Florida. American Fisheries Society Introduced Fish Section Newsletter 14: 2-3.
Freeman, S. and W. Alevizon. 1983. Aspects of the territorial behavior and habitat distribution of the fairy basslet, Gramma loreto. Copeia 1983: 829-831.
Mooi, R. D. and A. C. Gill. 2002. Grammatidae. Basslets. Pages 1370-1373 in: Carpenter, K. E. (Ed.). The living marine resources of the western central Atlantic. Volume 2. Bony fishes part 1 (Acipenseridae to Grammatidae). FAO Species Identification Guide for Identification Purposes and American Society of Ichthyologists and Herpetologists Special Publication No. 5. Food and Agriculture Organization of the United Nations (FAO), Rome.
Nelson, J. S., E. J. Crossman, H. Espinosa-Pérez, L. T. Findley, C. R. Gilbert, R. N. Lea and J. D. Williams. 2004. Common and Scientific Names of Fishes from the United States, Canada and Mexico. American Fisheries Society, Special Publication 29, Bethesda, MD.
Randall, J. E. 1996. Caribbean Reef Fishes. Third Edition. TFH Publications, Inc., Neptune City, New Jersey.
Reef Environmental Education Foundation (REEF). 2008. Exotic species sighting programs and volunteer database. World wide web electronic publication. www.reef.org, date of download March 10, 2008.
Smith-Vaniz, W. F., B. B. Collette and B. E. Luckhurst. 1999. Fishes of Bermuda: History, Zoogeography, Annotated Checklist, and Identification Keys. American Society of Ichthyologists and Herpetologists Special Publication No. 4.
Starck, W. A. II. 1968. A list of the fishes of Alligator Reef, Florida with comments on the nature of the Florida reef fish fauna. Undersea Biology 1: 5-40.
Webster, M. S. 2003. Temporal density dependence and population regulation in a marine fish. Ecology 84: 632-628.
Webster, M. S. 2004. Density dependence via intercohort competition in a coral-reef fish. Ecology 85: 986-994.
Webster, M. S. and M. A. Hixon. 2000. Mechanisms and individual consequences of intraspecific competition in a coral-reef fish. Marine Ecology Progress Series 196: 187-194.
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.