Canthigaster criobe, Williams, Jeffrey T., Delrieu-Trottin, Erwan & Planes, Serge, 2012

Williams, Jeffrey T., Delrieu-Trottin, Erwan & Planes, Serge, 2012, A new species of Indo-Pacific fish, Canthigaster criobe, with comments on other Canthigaster (Tetraodontiformes: Tetraodontidae) at the Gambier Archipelago, Zootaxa 3523, pp. 80-88 : 82-84

Canthigaster criobe new species

Common Name: Striped toby ( Figure 1 , 2 )

Holotype: USNM 400521, 38.7 mm SL when fresh (37.6 mm SL after preservation), Gambier Archipelago, Kouaku Island, on SE side of archipelago, small surge channel in outer reef; 23.22°S, 154.88°W; 15–20 m depth; field number GAM-2010-01; tissue sample number GAM-001; collected by S. Planes, J.T. Williams, E. Delrieu- Trottin, M. Kulbicki, P. Sasal. 29 September 2010.

Diagnosis: Dorsal rays 9; anal rays 9; pectoral rays 17; body depth between origins of dorsal and anal fins 2.6 in SL; head length 2.3 in SL; fleshy pigmented skin interorbital width 3.1 in HL; gill opening 8.2 in HL; origin of anal fin posterior to rear base of dorsal fin 3.1 in SL, the preanal length 1.2 in SL; longest dorsal ray 2.3 in HL; color in life: body pale tan with orangish brown stripes; head with uniformly orangish brown snout anteriorly, at middle of snout about 4 narrow, orangish brown stripes radiate posteriorly below eye, three stripes extend posteriorly from rear margin of eye, one stripe runs along ridge of erectile tissue on top of head, at deepest part of body there are about 14 narrow orangish brown stripes, middle five of those stripes continue to base of caudal fin where they abruptly end.

Description: Dorsal rays 9; anal rays 9; dorsal and anal rays branched, except the first; principal caudal rays 9, all branched but lowermost; a single small segmented upper and lower procurrent caudal ray; pectoral rays 17 (on right side; 16 on left, but left side appears to have been damaged earlier in life and healed, possibly losing a ray in the middle); vertebrae 17; mouth small, oval, and terminal, exposing about terminal half of upper dental plate; lips fleshy and papillose.

Body depth between origins of dorsal and anal fins 2.6 in SL; body moderately compressed, the width 1.6 in depth; head length 2.3 in SL; snout length 1.7 in HL; dorsal profile of snout slightly concave; eye diameter (unpigmented skin over eye) 3.9 in HL; bony orbit diameter 3.0 in HL; interorbital space slightly concave, the least bony interorbital width 3.7 in HL; gill-opening length 8.2 in HL; caudal-peduncle depth 2.3 in HL; caudalpeduncle length 2.7 in HL; predorsal length 1.3 in SL; dorsal-fin base 4.9 in HL; third dorsal ray usually longest, but adjacent rays nearly as long, 2.3 in HL; origin of anal fin below rear base of dorsal fin, the preanal length 1.2 in SL; anal-fin base 6.2 in HL; fourth anal ray longest, but adjacent rays nearly as long, 2.7 in HL; caudal fin truncate, 3.4 in SL; upper and lower portions of pectoral fins rounded, fin deeply incised in the middle; third pectoral ray longest, 2.5 in HL.

Skin with numerous small spinules directed posteriorly, each fitting into a longitudinal groove; skin smooth when stroked posteriorly, but spinules apparent when stroked anteriorly; spinules densely cover head, nape and belly, but are absent from the body immediately behind the pectoral-fin base and from body posterior to an imaginary line between origin of dorsal fin and origin of anal fin.

Color of holotype when fresh shown in Fig 1 . Body pale tan with orangish brown stripes; head with uniformly orangish brown snout anteriorly, at middle of snout about 4 narrow, orangish brown stripes radiate posteriorly below eye, three stripes extend posteriorly from rear margin of eye, one stripe runs along ridge of erectile tissue on top of head, at deepest part of body there are about 14 narrow orangish brown stripes, middle five of those stripes continue to and end abruptly at base of caudal fin; lips brown; orangish brown coloration on snout becomes paler, but continues posteriorly across chest and abdomen as a diffuse orangish tint that reaches anus; fins unpigmented and translucent; base of dorsal fin with a poorly developed dark blotch.

Color of holotype in alcohol similar to life colors except stripes are dark brown on tan background.

Etymology: We name this species criobe after the Centre de Recherche Insulaire et Observatoire de l'Environnement ( CRIOBE ), Moorea, French Polynesia, in recognition of the laboratory’s continuing support of marine research in French Polynesia. The species name is treated as a noun in apposition.

Remarks: Although it is known from only a single specimen, the longitudinally striped color pattern of Canthigaster criobe is unique within the genus and easily distinguishes C. criobe from all other described Canthigaster species. Although C. janthinoptera has its body covered with blue centered white spots, the orangish brown reticulations are similar in color to the stripes of C. criobe . In both of these species the base of the caudal fin has narrow brown lines extending onto the bases of the fin rays ( Figs. 1 , 3 ). Some specimens of C. janthinoptera have a few lines on the upper part of the body ( Fig. 3 ), but never a striped pattern like that of C. criobe . Canthigaster criobe and C. janthinoptera , along with the Hawaiian endemic C. jactator form a species complex within Canthigaster .

Figures

FIGURE 1. Holotype of Canthigaster criobe, USNM 400521, 38.7 mm SL, Gambier Archipelago (J. T. Williams).

FIGURE 2. Radiograph of holotype of Canthigaster criobe, USNM 400521, 38.7 mm SL, Gambier Archipelago, showing skin spinule pattern (J. T. Williams).

FIGURE 3. Canthigaster janthinoptera, USNM 400502, 50.6 mm SL, Gambier Archipelago (J. T. Williams).