Slippery dick explained

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 35cm (14inches).It has a thin, elongate body with a terminal mouth, and its body coloration has three phases during its life:

1. 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.^[1]
2. 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.^[2]
3. 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.^[3]

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 1to, but it's not very common in seagrass.^{[4] [5]}

Biology

This species feeds on benthic invertebrates, including crabs, small fishes, sea urchins and ophiuroids, polychaetes, and gastropods.^{[5] [6]}

It is a protogynous hermaphrodite. These fish form leks while breeding. In North Carolina, males defend temporary territories with peak spawning in May and June. Pair spawning typically occurs between females and terminal phase males; initial phase males occasionally try to insert themselves into the spawning event.

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

• Caribbean Diving Guide
• Marine Species
• Fish Base
• EOL.org

Notes and References

1. Randall, J.E. (1996). Caribbean reef fishes. T.F.H. Publications, Inc. Ltd., Hong Kong. 3rd ed.
2. http://biogeodb.stri.si.edu/bocas_database/search/species/1319 Smithsonian Tropical Research Institute Bocas del Toro Species Database
3. http://species-identification.org/species.php?species_group=caribbean_diving_guide&id=258 Marine Species Identification Portal : Slippery dick – Halichoeres bivittatus
4. Lieske, E. and R. Myers, 1994. Collins Pocket Guide. Coral reef fishes. Indo-Pacific & Caribbean including the Red Sea. Harper Collins Publishers, 400 p.
5. Böhlke, J.E. and C.C.G. Chaplin (1993). Fishes of the Bahamas and adjacent tropical waters. 2nd edition. University of Texas Press, Austin.
6. Cervigón, F. (1993). Los peces marinos de Venezuela. Volume 2. Fundación Científica Los Roques, Caracas, Venezuela.