Bucktooth Parrotfish
Sparisoma radians
    Ecological Descriptors
Habitat Size (cm) Diet Behaviour Sex 
Seagrass 20 (see below) Veg Sh PGH
All: All phases are highly variable and can also change colour rapidly according to surroundings.
Terminal phase
Blue bar from mouth to eye and blue spot behind eye. Greenish back and paler belly. Can have dark margin on tail and can display black on anterior underside. Black base to pectoral fins.
Initial  phase: Back brown, often mottled and blotched with paler underside.

This species is found in small schools, forming probable harems. Juveniles and adults inhabit sea grass beds, (possibly also mangrove areas), and shallow waters to depths of 12 m. Terminal pases (TP) are frequently seen at only ~5cm (2") in Antigua.

Very abundant and almost exclusively associated with dense stands of seagrass and macroalgae upon which it feeds during daylight hours. At night the fish remain quiescent on the bottom, hidden among the blades of seagrass. It tends to form permanent groups likely consisting of a dominant territorial terminal phase male and a series of smaller males and females. These groups are associated with particular areas of seagrass - striking given the unstructured nature of the seagrass beds.

Seagrasses account for 88% of adult individuals' diets with a preference hierarchy of: (1) Thalassia testudinum (Turltle Grass) with epiphytes, (2)  Halodule wrightii (Shoal Grass) ,(3) T. testudinum without epiphytes, (4)  Syringodium filiforme (Manatee Grass), and the algae, (5) Dictyota divaricata, (6) Enteromorpha flexuosa, (7) Caulerpa rnexicana, (8) Halimeda incrassata and (9) Penicillis pyriformis. Fish show differential survival paralleling the preference hierarchy, the most preferred plants leading to longest survival when choice is limited..

This Parrotfish species has a high tolerance to low salinities

Life Cycle:
Sparisoma radians reaches sexual maturity at approximately 75 mm. A protogynic hermaphrodite, with sex change (some individuals only)  at around 63 mm. It is a monandric parrotfish, with all males secondarily derived from females unlike e.g. the Rainbow Parrotfish (cf).  It participates in both pair and group spawning. Females form permanent harems. During spawning, male individuals release 8.9 x 106 sperm when pair spawning.

Bucktooth Parrotfish IP
Bucktooth Parrotfish TP
Bucktooth Parrotfish TP
(C) Van Tassell & Robertson