The slippery dick ( Halichoeres bivittatus) is a species of wrasse native to shallow, tropical waters of the western Atlantic Ocean.
Description
The slippery dick wrasse is a small fish that can reach a maximum length of .
It has a thin, elongate body with a terminal mouth, and its body coloration has three phases during its life:
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The terminal phase is when the fish becomes a male, so the body coloration turns to green with two longitudinal dark stripes. The head and tail are covered with pink lines; it has a small black dot up to the pectoral fin.
[Randall, J.E. (1996). Caribbean reef fishes. T.F.H. Publications, Inc. Ltd., Hong Kong. 3rd ed.]
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The initial phase is when the juvenile becomes a female. The background body coloration is mainly whitish with pink shade, and the sides have two dark longitudinal stripes. The median one is usually black extending from the snout and via the eye to the base of the tail. The second one is a paler lateral stripe further below. The upper stripe incorporates a bicolored (green and yellow turning later to black) spot where it crosses the edge of the gills (this is present in all phases).
[ Intermediates vary greatly, from shades of light purple to dark brown. Juveniles are usually white and have two dark stripes, but the lower (abdominal) stripe may be faint.][ Smithsonian Tropical Research Institute Bocas del Toro Species Database. Biogeodb.stri.si.edu (2013-09-19). Retrieved on 2018-01-07.]
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The juvenile phase. The body is usually whitish, still with the two longitudinal stripes and the spot up to the pectoral fin, as in the initial phase.
[ Marine Species Identification Portal : Slippery dick – Halichoeres bivittatus. Species-identification.org. Retrieved on 2018-01-07.]
Distribution and habitat
The slippery dick wrasse is widespread throughout the tropical and subtropical waters of the western
Atlantic Ocean. It can be found from
North Carolina and
Bermuda to
Brazil,
[ including the Gulf of Mexico and the Caribbean Sea area.
]
The slippery dick wrasse is generally reef-associated at depths from , but it's not very common in seagrass.[Lieske, E. and R. Myers, 1994. Collins Pocket Guide. Coral reef fishes. Indo-Pacific & Caribbean including the Red Sea. Harper Collins Publishers, 400 p.][Böhlke, J.E. and C.C.G. Chaplin (1993). Fishes of the Bahamas and adjacent tropical waters. 2nd edition. University of Texas Press, Austin.]
Biology
This species feeds on benthic invertebrates, including crabs, small fishes, sea urchins and Brittle star, , and Gastropoda.[Cervigón, F. (1993). Los peces marinos de Venezuela. Volume 2. Fundación Científica Los Roques, Caracas, Venezuela.]
Sex change
It is a protogynous hermaphrodite.
Reproduction
Both terminal and initial phase male will reproduce, but while terminal phase males usually spawn in pairs within territories that they defend, initial phase males usually spawn in large groups. Terminal phase males may also occasionally join group spawning events, and initial phase males occasionally interfere with the pair spawning of terminal males.
These fish form leks while breeding.
Status and threats
This species is widespread and very common throughout much of its range in the Caribbean and Florida, although it is uncommon in northeastern Brazil. There are no major threats known to this species, and population trends are unknown. It is listed as Least Concern (LC) by the IUCN.
External links
