Diamond Watchman Goby [A Comprehensive Guide]

Diamond Watchman Goby

Diamond Watchman Goby, also known as Orange-spotted Sleeper-goby, Orange-dashed Goby, or Maiden Goby, is a marine fish species found in the Indian and western Pacific Oceans.

It lives in lagoons and outer reefs with sandy bottoms and large rubble for burrowing.

Diamond Watchman Gobies are also popular in the aquarium trade and are reef-safe. Their diet consists of zooplankton, dead fish, and insects.

These fish prefer clear water areas and are found in pairs, using shallow burrows under rubble as shelter.

They are also found in places with dark volcanic sand like the Philippines, Indonesia, and the Northern Mariana Islands.

Diamond Watchman Goby Interesting Facts

  • Diamond Watchman Gobies grow up to 7.9 inches (20.0 centimeters) long and live in lagoons with sandy bottoms.
  • They are popular aquarium fish, feeding on zooplankton, dead fish, and insects.
  • These monogamous fish prefer water temperatures between 72°F to 79°F (22°C to 26°C).
  • Their appearance varies depending on their location in the Indian or western Pacific Oceans.

Diamond Watchman Goby Habitat

Diamond Watchman Goby is found in the Indo-Pacific region, specifically from the Red Sea to Samoa.

Its habitat range extends north to southern Japan and south to the Great Barrier Reef and New Caledonia. This fish lives in marine environments, particularly near coral reefs.

It usually swims at depths of 10 to 30 meters (33 to 98 feet) but is also found between 2 to 84 meters (6 to 275 feet).

Diamond Watchman Goby prefers water temperatures of 72°F to 79°F (22°C to 26°C) and is found in tropical areas between latitudes of 32°N to 24°S.

Water Temperature:72°F to 79°F (22°C to 26°C)
Water pH:Unknown
Water Hardness:Unknown

Diamond Watchman Goby Physical Characteristics

Size: 7.9 inches (20.0 centimeters)

Diamond Watchman Goby grows up to 7.9 inches (20.0 centimeters) long. It has 7 dorsal spines, 11 to 12 dorsal soft rays, 1 anal spine, and 11 to 12 anal soft rays.


  • Pacific Diamond Watchman Gobies have a pale grey body with large orange spots on the side, dash-like markings below, smaller orange spots on the back, and blue-to-white streaks or spots on the head.
  • Indian Ocean Pacific Diamond Watchman Gobies have a pale blue-grey body with an orange stripe across the lower head, blue markings on cheeks, and orange bars connected to a pale orange stripe on the lower half of their body.

Other Characteristics

  • The third dorsal spine is longest in young Diamond Watchman Gobies, under 40 mm,
  • The rounded caudal fin measures about 3.0 to 4.2 times in standard length (SL),
  • There are 79 to 91 scales along the lateral line,
  • Body scales are ctenoid but become cycloid before the first dorsal fin, lower side, and the midline of the abdomen,
  • Head and midline of the nape lack scales. However, there are some scales on the sides of the nape extending above the middle of the operculum (gill cover),
  • Pectoral fin base are without scales,
  • Prepelvic area is partly or fully covered with scales, and
  • Body depth ranges from around 4.8 to 6 times Standard Length (SL).

Diamond Watchman Goby Reproduction

Diamond Watchman Goby mates only with one partner, which is seen as necessary and social behavior.

Diamond Watchman Goby Scientific Classification

Scientific Name:Valenciennea puellaris
Also Known As:Diamond Watchman Goby, Orange-spotted Sleeper-goby, Orange-dashed Goby, Maiden Goby
Conservation Status:Least Concern

Leave a Comment

Your email address will not be published. Required fields are marked *