Satyrichthys kikingeri, Pogoreutz, Claudia, Vitecek, Simon & Ahnelt, Harald, 2013

Pogoreutz, Claudia, Vitecek, Simon & Ahnelt, Harald, 2013, A new species of Satyrichthys (Teleostei: Peristediidae) from the Maldives Archipelago (Indian Ocean), Zootaxa 3694 (4), pp. 153-160 : 155-158

Satyrichthys kikingeri sp. nov.

Kikinger’s robust-armed gurnard ( Figs. 1 , 2 ; Tables 1 , 2)

Holotype. NMW 96546, 442 mm SL with rostral projections, 428 mm without; Maldives Archipelago, Rasdhoo Atoll, Madivaru Channel, 4°15’52’’N, 73°0’1.6’’E, collected May 4, 2012.

Diagnosis. A Satyrichthys with (1) three lip and 0/1 chin barbels, (2) bony plates in the upper lateral row of the caudal peduncle with forward directed spines, (3) parietal bones unequal in size on midline, (4) no dusky spots on head, trunk, tail or fins.

Description. Measurements, proportional values and counts of the holotype are provided in Table 1 and Table 2 respectively.

Body fusiform, tapering, covered with bony plates arranged in four longitudinal rows. All plates with posteriorly directed spines except the last five plates in the dorsal and ventral rows; 21st to 28th plates in upper lateral row with doubled spines, the anterior forward-oriented. First dorsal fin originating between first and second bony plates of the dorsal row. The two ventral free rays of the pectoral fin are thickened and the dorsal free ray longer than the ventral ray. Caudal fin small, emarginate with posterior lobe longer than ventral lobe ( Fig. 2 ).

Head large, depressed, with expanded edges. Rostral projections short, flat and wide with rounded tips pointing inwards. Distance between rostral projections less than interorbital distance at the base ( Fig. 2 B). Mesethmoid with one tiny, barely discernible mesethmoid spine. Frontal with one small supraorbital spine located dorsally of posterior quarter of orbit. Lateral ridge of parietal ends in a distinct parietal spine. Posttemporal ends in a weak spine. Nuchal plate (first plate of dorsal row) bearing a small nuchal spine dorsal of the second bony plate of the upper lateral row. Opercle with two conspicuous opercular spines, upper slightly shorter than lower. Preopercular ridge ending posteriorly in a single short preopercular spine; extending anteriorly on the infraorbitals 2 and 3 to about dorsal of the angle of the mouth, and separated from the ridge extending posteriorly from the rostral projections (infraorbital 1) by a short gap.

Mouth large, inferior. Lower jaw not reaching below orbit. Premaxilla, dentary, vomer, palatine toothless. Isthmus between gill membranes wide. Three barbels on lower lip. Anterior two barbels short and unbranched, posteriormost barbel long and branched. One small single barbel on left side of chin. Formula for barbels: 3/3 - 1/0 (the slash separates barbels of the left and the right mandible) ( Fig. 3 ).

Coloration. Description of coloration is based on pictures taken shortly after collecting the dead specimen and after preservation. Head, body, and fins uniformly bright red orange after collection, ventral surfaces white. Color of specimen preserved in 4 % seawater-buffered formaldehyde pale fawn. No body markings have been identified before or after preservation.

Etymology. Named for the marine biologist and conservationist Dr Reinhard Kikinger who headed the previous biostation and current EcoCentre at Kuramathi Island Resort in Rasdhoo Atoll, Maldive Islands, from 1999-2012.

Distribution. Known only from Rasdhoo Atoll in the Maldives Archipelago, depth unknown.

Remarks. Satyrichthys kikingeri sp. nov. differs from its congeners in the combination of the following characters: (1) 3/3 lip and 0/1 chin barbels, (2) 15 fin rays in the second dorsal fin, 13 fin rays in the anal fin, (3) 25 bony plates in the dorsal, 29 in the upper lateral and 20 in the lower lateral and ventral rows, (4) 21st to 28th bony plates in the upper lateral row with forward directed spines, (5) parietal bones unequal in size on midline and (6) shape of emarginated caudal fin with dorsal lobe longer than ventral lobe.

Similar species. An important character in separating species of the genus Satyrichthys is the number of lip and chin barbels (Miller 1964, Kawai 2008, 2013). With only one or two lip barbels S. longiceps , S. clavilapis and S. rieffeli differ from all other Satyrichthys species which are characterized by at least 3 lip barbels on both sides of the lower jaw.

With three lip barbels S. kikingeri is most similar to S. laticeps , S. milleri , S. moluccense and S. welchi (Kawai 2013) but is easily separated from S. milleri and S. welchi .

S. kikingeri differs from S. milleri in the number of lip and chin barbels (3/3 and 1/0 vs. 4–5/4–5 and 4/4), number of anal fin rays (13 vs. 15–17), number of preopercular spines (1 vs. 1–2) and the shape of posterior spines of the dorsal row (doubled vs. single)

S. kikingeri differs from S. welchi in the number of lip and chin barbels (3/3 and 1/0 vs. 4/4 and 3/3), the number of dorsal (15 vs. 17–19) and anal (13 vs. 17–18) fin rays, the size of the parietal bones (different size of both parietals vs. same size) and in the coloration of the dorsal fins (uniformly colored vs. dusky spots).

Meristic characters total number Dorsal fin rays VII + 15 Anal fin rays 13

Pectoral fin rays (including two free rays) 15

Pelvic fin rays I + 5 Caudal fin rays 12

Bony plates in dorsal row 25

Bony plates in upper lateral row 29

Bony plates in lower lateral row 20

Bony plates in ventral row 20

Bony plates before anus 2

Bony plates in upper lateral row with forward directed spines 8 (21st–28th) Upper gill rakers 5

Lower gill rakers including the one at angle 17

Lip barbels (left/right) 3/3 Chin barbels (left/right) 1/0 Longest lip barbel bearing X/X flagella (left/right) 8/8 Branchiostegal rays 6

S. kikingeri is obviously close to S. moluccense and S. laticeps but distinguishable on meristic and morphometric characters ( Tables 1 , 2).

S. kikingeri and S. moluccense have the same number of lip barbels in common and differ slightly in the number of chin barbels (1/0 vs. 0 or 2/0 or 2). Both species differ in the number of second dorsal (15 vs. 17–18) and anal (13 vs. 17–19) fin rays, number of bony plates in the upper lateral (29 vs. 31–34) and dorsal (25 vs. 26–28) rows, the size of the parietal bones (different size of both parietals vs. same size) and in body proportions (%HL / %SL) ( Table 1 , Kawai 2013), e.g. body depth (54.5% vs. 39.1–51.1% / 22.7 vs. 16.2–20.8%), body width (55.7% vs. 32.6–44.4% / 23.2% vs. 13.3–17.7%), head depth (54.9% vs. 35.8–49.9% / 22.9% vs. 16.7–20.3%) or distance from snout to anus (141% vs. 113.8–128.3% / 58.8% vs. 46.4–52.6%).

S. kikingeri and S. laticeps have in common that the parietal bones are of different sizes. Both species differ in the number of lip and chin barbels (3/3 and 1/0 vs. 4–5/3–4 and 2–5/2–4) and number of anal fin rays (13 vs. 14– 17). It should be noted that the typical number of lip barbels for S. laticeps is obviously 4/4. Kawai (2013) investigated 53 specimens and found only 1 specimen with 5 lip barbels on the left and one specimen with 3 lip barbels on the right side. Both species have similar body proportions (%SL) ( Table 1 , Kawai 2013) but differ e.g. in the width of body (23.2% vs. 12.4–20.3%), distance from snout to anus (58.8% vs. 46.2–53.6%) or caudal peduncle depth (4.2% vs. 2.2–3.4%).

Four unidentified specimens of Satyrichthys were collected in 1991 at the North Male Atoll ( Maldives) in a depth of 180 m (Anderson et al. 1992). The largest and the smallest of these were deposited at the Bernice Pauahi Bishop Museum at Honolulu, Hawaii (BPBM 34965) (Adam et al. 1998). Their taxonomic status is discussed elsewhere. The whereabouts of the two other specimens is unknown. These four specimens document the first record of this genus for the Republic of the Maldives. Adam et al. (1998) report Satyrichthys investigatoris from the Maldives, a species now placed in the genus Scalicus (Kawai 2008) .

Ecology. The single specimen of S. kikingeri was found floating dead on the surface. Therefore no ecological data are associated with this sample and the exact depth inhabited by this species is unknown. Dead Satyrichthys sp. specimens are occasionally found on the beaches of Maldivian islands (Adam et al. 1998). Rasdhoo Atoll is located north-west of North Ari Atoll, west of the deep inner sea basin dividing the Maldives Archipelago into two north-south oriented chains of atolls (Anderson et al. 2011) ( Fig. 1 ). Given the lifestyle of other known Peristediidae , the appearance of the specimen, and the availability of appropriate habitat, it is likely that S. kikingeri is a deep-water form.

Figures

FIGURE 1. Collection site of Satyrichthys kikingeri. (A) Location of Rasdhoo Atoll, Ari Atoll in the Maldives Archipelago. Adapted from Anderson et al. (2011). (B) Rasdhoo Atoll, North Ari Atoll, Maldives. The collection site off Madivaru in Madivaru Channel is marked with a filled asterisk. Adapted from Gischler (2006).

FIGURE 2. Holotype of Satyrichthys kikingeri, NMW 96546, 442 mm SL with rostral projections, 427.7 mm without rostral projections; Maldives Archipelago. (A) Lateral view. (B) Dorsal view.

FIGURE 3. Illustration of the ventral side of the lower jaw, showing barbel arrangement of the holotype of Satyrichthys kikingeri, NMW 96546, 442 mm SL with rostral projections, 427.7 mm without rostral projections. Maldives Archipelago.

Tables

TABLE 1. Morphometric measurements for the holotype of Satyrichthys kikingeri.

Morphometric characters	length [mm]	% in SL	% in HL
Standard length	427.7	100.0
Body depth	97.1	22.7	54.4
Body width	99.2	23.2	55.7
Head length	194.9	41.7	100
Head depth	97.8	22.9	54.9
Head width	134.2	31.3	75.3
Distance from snout to origin of first dorsal fin	196.2	41.2	98.8
Distance from snout to origin of anal fin	284.3	59.6	143.1
Distance from snout to anus	280.1	58.8	141.0
Distance from anus to origin of caudal fin	172.3	40.3	96.7
Snout length	95.1	22.2	53.4
Rostral Projection length	24.2	5.7	13.5
Longest barbel length	52.3	12.2	29.3
Upper jaw length	70.4	16.5	39.5
Lower jaw length	69.9	16.3	39.2
Orbital diameter	32.6	7.6	18.3
Interorbital width	33.9	7.7	19.0
Preopercular spine length	25.1	5.9	14.1
Pectoral fin length	80.2	18.8	45.0
Length of dorsal detached pectoral fin ray	54.1	12.6	30.4
Length of ventral detached pectoral fin ray	41.9	9.8	23.5
Pelvic fin length	71.8	16.8	40.3
Length of first dorsal spine	49.3	11.5	27.2
Caudal fin length	52.2	12.2	29.3
Caudal peduncle length	43.3	10.1	24.3
Caudal peduncle depth	18.1	4.2	10.2
Length of base of first dorsal fin	56.4	13.2	31.6
Height of first dorsal fin	48.0	11.2	26.9
Length of base of second dorsal fin	148.2	34.7	83.2
Heigth of second dorsal fin	26	6.1	14.6
Length of base of anal fin	137.5	32.1	77.2
Height of anal fin	29.1	6.8	6.3