Auffallend einzelner rötlicher Fleck (Ocellus) an der Flanke. Oben und an der Seite eine dunkelgrüne oder bläulich-grüne Grundfärbung, die vom weißen Bauch deutlich abgegrenzt ist. Oft ist der Rand des schwanzes Orange eingefärbt.
Monotrete cambodgiensis unterscheidet sich von der sehr viel häufigeren Art Monotrete leiurus nur durch die Körperzeichnung. Da Monotrete leiurus je nach Vorkommensgebiet aber sehr verschiedene Zeichnungen haben kann, und einige Farbmorphen der von M. cambodgiensis sehr ähneln, ist eine unterscheidung nicht gerade leicht.
Roberts 1989 nutzt für M. cambodgiensis das Synonym â€œTetraodon barbatus und für Monotrete leiurus das Synonym â€œTetraodon leiurus. Siehe auch M. leiurus!
â€žDistinguished from other species of genus in Laos by: - conspicious single ocellus on flank / - dark green or bluish-green back and side, sharply demarcated from immaculate white belly / - upper margin of caudal often orange. Size up to 153 mm SL.â€œ (Kottelat 2001, S. 166)
â€œTetraodon barbatus is distinguished here from its close relative T. leiurus only by coloration, but the differences are striking. Tetraodon leiurus is extremely variable in coloration, sometimes approaching but never with overall coloration quite like that of T. barbatus. Tetraodon barbatus, on the other hand, shows remarkably little variation in color. All of the type specimens collected by me were observed while still allive. The dorsal surface varies from vivid turquoise blue to greenish blue or green. The ventral surface is uniformly milky white. The dorsal and ventral coloration of head and body are sharply demarcated and the devision between them very straight and regular. The single ocellated spot on the flank, retained troughout life, is always red-centered. No other ocelli or spots on the body. Every on of the specimens of T. barbatus (including juveniles of only 27 mm SL) has lower lip with three close-set but distinct black marks (a large median spot and two smaller lateral spots). Coloration of T. leiurus may be desribed here to facilitate comparison with T. barbatus. Tetraodon from the middle portion of the Mekong basin-where T. barbatus also occurs, often sympatrically- almost never exhibit even faint marks on the chin similar to the three bold marks of T. barbatus. The chin is either uniformly dusky or dirty white, or with very indistinct marks (...) The color on the dorsal body surfaceis never a vivid color but always dusky, dark, grayish or brownish, ans usually spotted. The abdomen is never milky white, but off-white, yellowish, or dusky often with numerous faint dusky spots. The demarcation between the dorsolateral and ventral coloration of head and body is usually highly irregular, not all straight, due mainly to the many spots or mottlings. The center of the ocellated spot on the flank, always red in small juveniles, may retain this color in adults or change to green or blue. Often there are additional ocellated spots. Some specimens of T. leiurus from lower Mekong, the Meklong, and the Tapi basin in peninsular Thailand have three chin markings identical in size and position to the three bold chin marks in T. barbatus. These marks in T. leiurus are relatively dusky or pale and less sharply demarcated. Other color features of these specimens, including color in life and demarcation of dorsal and ventral portion of color pattern on body, are quite unlike T. barbatus. Specimens of T. leiurus from the middle Mekong generally do not have the dorsal and ventral portions of the body coloration sharply demarcated, but such demarcation occurs in specimens from the Tonle Sap in Cambodia. These Tonle Sap specimens do not have the same color in life as T. barbatus and they have no marks on the chin. (Roberts 1998, S. 230-231, dort erwähnt als Tetraodon barbatus)