Syncomistes moranensis, Shelley & Delaval & Le, 2017

Shelley, James J., Delaval, Aurélien & Le, Matthew C., 2017, A revision of the grunter genus Syncomistes (Teleostei, Terapontidae, Syncomistes) with descriptions of seven new species from the Kimberley region, northwestern Australia, Zootaxa 4367 (1), pp. 1-103 : 58-63

Syncomistes moranensis , new species

( Tables 21 , 22, S22 & S 23 ; Figures 20 & 21 )

Corresponds to the nominated taxa code ‘ Syncomistes sp. 4’ of Shelley (2016).

English vernacular name: Moran Grunter.

Holotype: NMV A.31448-011 , 178 mm SL, Mid Moran, Moran River , 15° 22' 33.97'' S, 125° 44' 29'' E. The holotype was obtained with gill nets and electrofishing in a deep slightly turbid pool over sandstone substrate by J. J. Shelley and M. C. Le Feuvre, July 22, 2013.

Paratypes: Eight specimens, 112–186 mm SL. All paratype material was collected in line with the holotype. WAM P.34539.002 (3), 112–179 mm SL, NTM S.18111-001 (1), 176 mm SL, NMV A.31448-011 (1), 186 mm SL, NMV A.31448-012 (1), 161 mm SL, NMV A.31448-013 (1), 156 mm SL, NMV A.31448-014 (1), 132 mm SL, Mid Moran , Moran River, 15° 22' 33.97'' S, 125° 44' 29'' E.

Diagnosis: A large species of Syncomistes (recorded up to 250 mm SL, commonly 150–200 mm SL). Syncomistes moranensis sp. nov. differs from all other species within the Syncomistes complex by a combination of the following characters: jaw of adults rounded with a tapered point when viewed from below (jaw shape of juveniles unknown) ( Fig. 5b ); mouth terminal; mouth slightly oblique; teeth conical ( Fig. 6i ); longest dorsal ray <15.7 % SL; longest dorsal spine <12.2 % SL; pectoral fins <22.5 % SL; upper caudal lobe <26.6 % SL; restricted to the Moran River within the Roe River catchment in the Kimberley region.

Description: See Table 21 for a summary of meristic variation by type material and other material examined and Table S22 meristic variation across all specimens combined. Dorsal fin spines XII, rays 12 (11–12); anal fin spines III, rays 8 (7–8); caudal fin rays 10+8+7+12 (10–13+8+7+11–13, n = 8); pectoral fin rays 15 (15–16); pelvic spines I, rays 5; vertebrae 11+14 = 25 (10–11+14–15=24–26, n = 8); lateral line scales 49 (48–50); scales above lateral line 11 (10–11); scales below lateral line 20 (18–10); pre-dorsal scales 16 (12–18); cheek scale rows 5 (4–6); caudal peduncle scales 31 (30–32); gill rakers on first arch 9+20 = 29 (8–11+18–20 = 26–30); opercular spines 2; preopercular spines 20 (12–32).

See Table 22 for a summary of morphometric variation by type material and other material examined and Table S23 morphometric variation across all specimens combined. Large species of Syncomistes . Steeply angled dorsal profile of head, runs ~45° relative to horizontal plane. Dorsal profile straight from tip of snout to occiput and further to nape above preopercle edge, convex to dorsal fin origin, convex to posterior of last dorsal ray base, then horizontal to caudal fin base. Ventral profile convex from tip of snout to base of last dorsal fin ray, then horizontal to caudal fin base. Lateral line continuous from behind head to base of caudal fin, and approximately parallel to dorsal profile. Body depth at dorsal fin origin 33.3 (30.1–35.6) % SL; body depth at anal fin origin 29.2 (24.1– 32.4) % SL; caudal peduncle length 18.3 (16.9–20.1) % SL; caudal peduncle depth 12.8 (11.1–13.4) % SL; preanus length 67.6 (66.0–71.5) % SL. Head length 31.3 (30.2–32.7) % SL; head pointed. Snout length 41.0 (40.0– 42.0) % HL; upper-jaw length 31.3 (29.6–33.2) % HL; jaws equal throughout development; jaw width 34.8 (32.3– 37.3) % HL. Lower jaw rounded, tapering to slight point when viewed from below (Morphotype 2; Fig. 5b ), shape in juveniles (<65 mm SL) unknown. Mouth terminal with shallow upward angle in lateral profile. Upper lip fold thick and continuous. Lower lip less thick and discontinuous, being fleshy posteriorly and reducing gradually to no lip fold anteriorly. Teeth on outer row of upper jaw 71 (56–79) number varying with size, 3.6 (2.9–4.7) / mm when standardised with upper jaw length; teeth on outer row of lower jaw 57 (42–73), number varying with size also, 3.6 (2.9–4.7) / mm when standardised with upper jaw length; 5 (4–6) tooth rows behind outer row on upper jaw and 4 (3–5) on lower jaw; teeth conical, large relative to Syncomistes , symmetrical, ‘hour glass-shaped’, wide base, tapering to narrowest point at mid-point of tooth, widening again before tapering to a sharp point (Tooth Morphotype 5; Fig. 6i ); teeth fitted closely together but not overlapping, embedded in a sturdy ‘plate-like’ jaw. Toothless medial hump present on dorsal surface at symphysis of lower jaw, not very pronounced, with teeth present on opposite region of upper jaw. Teeth rows curve inwards towards throat at posterior end of mouth in lower jaw. Orbital diameter 18.7 (16.1–21.5) % HL; inter-orbital width 29.1 (24.9–32.5) % HL; inter-orbital smooth and not scaled; post-orbital length 42.6 (40.6–44.5) % HL. Lower opercular spine longer and more robust than upper opercular spine, sometimes extends beyond edge of opercular membrane; Preopercular spines serrate, longest and most robust on apex of preopercle, reducing in size dorsally and anteriorly, anteriormost spine around posterior edge of orbit. Intestinal pattern of adults highly convoluted; large amount of looping to left of stomach; juveniles with less convoluted pattern.

Dorsal fin origin posterior to vertical plane through pectoral fin origin, anterior to pelvic fin origin; terminates at base of last dorsal ray. Dorsal fin sheath scales 2 at mid-point, progressing to 3–4 rows posteriorly; 7th (5th–7th) dorsal spine longest, length 11.3 (10.3–12.2) % SL; progressively shorter towards first and last dorsal spine; last dorsal spine fully joined to first dorsal ray by membrane; 4th dorsal ray longest, length 14.4 (13.6–15.7) % SL; dorsal margin of rayed portion rounded to tip of last ray; dorsal fin base length 54.1 (51.6–56.2) % SL; dorsal fin length 60.5 (56.7–62.8) % SL; pre-dorsal fin length 39.6 (38.2–41.1) % SL. Anal fin origin immediately posterior to vertical plane through base of last dorsal fin spine; terminates at base of last ray; Anal fin sheath scales 4 (3–5) at mid-point, progressing from 1–3 rows anteriorly to 4–5 rows posteriorly; 2nd anal spine longest, length 12.4 (11.4– 14.2) % SL; 2nd anal ray longest (1st–3rd), 14.9 (13.1–16.5) % SL; rays progressively shorter to last ray; margin of rayed portion rounded; anal fin base length 15 (13.6–16.3) % SL; anal fin length 22.6 (20.9–24.1) % SL; pre-anal fin length 71.5 (69.6–74.0) % SL. Caudal fin slightly emarginate; Upper caudal lobe length 25.4 (23.3–26.6, n = 8) % SL; middle caudal ray length 18.5 (15.3–20.6) % SL. Pectoral fin length 20.7 (19.5–22.5) % SL; pre-pectoral fin length 30.1 (28.6–31.8) % SL. Pelvic spine length 10.3 (9.3–11.0) % SL; 1 st pelvic ray longest, 20.1 (18.7–21.5) % SL; pelvic fin length 21.8 (20.5–22.7) % SL; pre-pelvic fin length 39.2 (37.5–40.9) % SL.

Colour when fresh: Body dull gold overall with greenish sheen on head. Body darker dorsally, becomes lighter on the ventral surface. Five to six dark, wavy lines sometimes present on sides of adults: first following base of dorsal sheath; second, running from the anterior of nape to below posterior of soft dorsal ray base; third follows the lateral line ending on dorsal edge of caudal peduncle; fourth, from supracleithrum to middle of caudal base; fifth, running between the largest opercular spine and ventral edge of caudal peduncle; sixth running from dorsal edge of pectoral fin base to anus. Presence of lines highly variable and fading quickly once fish are removed from water or after death. Juvenile colouration unknown.

Anal fin with a basal blotch extending posteriorly on anterior rays. Caudal fin membranes dull gold. Dorsal fin membranes dull gold with dusky blotches. Pelvic fins dusky, pectoral fins clear. A silvery or gold stripe running below eye. Scales on body have a dark posterior band of pigmentation.

Colour when preserved: Juveniles and adults uniformly dark brown to black with hints faints hints of pale colouration on the ventral surface. Brown when viewed ventrally. Lateral line is may be distinctly pale or dark brown in colouration. All fins dark brown to black. Colouration of juveniles unknown.

Distribution: See Fig. 21 . Collected from one site in the middle of the Moran River catchment, a major tributary of the Roe River, northern Kimberley region, Western Australia. Sampling of the Roe and Moran rivers is very limited and thus the true distribution within the catchment is unknown.

Ecology: Prefers deep backwaters and slow flowing stream sections. Observed shoaling in the middle of the water column with Hephaestus jenkinsi . Found in clear waters over rocky substrates, where algae is abundant.

Comparison: The mouth, jaw, and tooth morphology of Syncomistes moranensis is similar to Syncomistes carcharus , and distinct from other Syncomistes species. Distinctive features include a terminal mouth, rounded jaw with a slightly pointed tip, a thick, fleshy lip fold on the upper and lower lip, robust teeth, tooth rows curving inwards towards the throat at the posterior end of the lower jaw, a less pronounced medial hump on the lower jaw, and the presence of teeth on the upper jaw opposite the medial hump. The tooth count relative to jaw length is significantly less than in other Syncomistes . Other distinctive features are a straight dorsal profile from the tip of the snout to the occiput and a greater pre-anus length 67.6 (66.0–71.5) % SL.

Although similar to Syncomistes carcharus , it differs by having, on average, markedly smaller relative orbital diameter 18.7 (16.1–21.5) % HL versus 20.6 (19.6–21.5) % HL and head length 31.3 (30.2–32.7) % SL versus 34 (32.9–34.7) % SL, as well as shorter relative fin measurements: dorsal spine length 11.3 (10.3–12.2) % SL versus 13.6 (13.4–14.0) % SL, pectoral fin length 20.7 (19.5–22.5) % SL versus 23.1 (22.8–23.8) % SL and upper caudal lobe 25.4 (23.3–26.6) % SL versus 30.6 (29.9–31.6) % SL. These differences are visually apparent.

Etymology: The specific name moranensis refers to the type locality, the Moran River, which is also the only known location of the species.

Remarks: The different dentition and mouth morphology of Syncomistes moranensis and Syncomistes carcharus resembles fishes from the genus Hephaestus (Vari 1978) . However, it retains the key diagnostic features of Syncomistes including: an enlarged, laterally flared outer row of teeth; toothless medial hump on the lower jaw opposite a groove on the upper jaw; horizontal body stripes; and a highly convoluted gut with 6 loops. Meristic counts were also typical of Syncomistes . Occurs in sympatry with S. trigonicus .

Figures

FIGURE 5.

FIGURE 6.

FIGURE 20

FIGURE 21.

Tables

TABLE 21. Summary of meristic variation in Syncomistes moranensis sp. nov. (values for number of teeth of upper and lower jaw are per mm of jaw length).

	Holotype	Paratypes (N = 8)
Character		Mode	Mean	Min.	Max.	S.D.
DS	12	12	12.0	12.0	12.0	0.00
DR	12	12	11.9	11.0	12.0	0.35
AS	3	3	3.0	3.0	3.0	0.00
AR	8	8	7.9	7.0	8.0	0.35
PecR	15	15	15.3	15.0	16.0	0.46
PelS	1	1	1.0	1.0	1.0	0.00
PelR	5	5	5.0	5.0	5.0	0.00
UUCR	12	12	11.4	10.0	13.0	0.93
UBCR	8	8	8.0	8.0	8.0	0.00
LBCR	7	7	7.0	7.0	7.0	0.00
LUCR	12	12	11.9	11.0	13.0	0.64
LLSc	48	49	48.9	48.0	50.0	0.83
LD	11	11	10.5	10.0	11.0	0.53
LA	20	18	18.4	18.0	19.0	0.52
PDSc	17	16	15.6	12.0	18.0	1.92
DSSc	2	2	2.0	2.0	2.0	0.00
ASSc	5	4	4.0	3.0	5.0	0.53
CScR	6	5	5.0	4.0	6.0	0.93
CPSc	31	31	30.9	30.0	32.0	0.83
GRup	9	9	8.6	8.0	9.0	0.52
GRlow	20	19	19.1	18.0	20.0	0.64
GRtot	29	28	28.0	26.0	30.0	1.20
PcV	11	11	10.8	10.0	11.0	0.35
CV	14	14	14.1	14.0	15.0	0.35
TV	25	25	25.0	25.0	25.0	0.00
LDR	4	4	4.0	4.0	4.0	0.00
LDS	7	6	6.0	5.0	7.0	0.53
LAR	2	2	1.6	1.0	3.0	0.74
LAS	2	2	2.0	2.0	2.0	0.00
LPR	1	1	1.0	1.0	1.0	0.00
Tup	4.0	4.4	4.5	3.9	5.5	0.49
Tlow	3.2	3.7	3.7	2.9	4.7	0.56
TRup	5	5	4.9	4.0	6.0	0.83
TRlow	4	4	4.0	3.0	5.0	0.53
OS	2	2	2.0	2.0	2.0	0.00
PS	23	19	19.6	12.0	32.0	6.35

TABLE 22. Morphometric variation in Syncomistes moranensis sp. nov. (values are percentages of denominators in ratios, except for SL).

	Holotype	Paratypes (N = 8)
Character		Mean			Min.	Max.	S.D.
SL (mm)	177.9	159.5			112.2	186.4
BDd / SL	32.0	33.5			30.1	35.6	1.95
BDa / SL	28.8	29.2			24.1	32.4	2.57
CPL / SL	17.7	18.3			16.9	20.1	1.10
CPD / SL	13.2	12.7			11.1	13.4	0.70
HL / SL	31.0	31.3			30.2	32.7	0.84
OD / HL	16.1	19.0			17.8	21.4	1.38
IoW / HL	28.3	29.2			24.9	32.5	2.09
PoL / HL	42.6	42.6			40.6	44.5	1.24
SnL / HL	41.5	40.9			40.0	42.0	0.74
JLup / HL	32.2	31.2			29.6	33.2	1.22
JW / HL	32.2	35.1			32.3	37.3	1.86
PDFL / SL	38.5	39.7			38.2	41.1	1.26
PPecL / SL	29.2	30.2			28.6	31.8	1.07
PPelL / SL	38.5	39.3			37.5	40.9	1.06
PAL / SL	66.0	67.8			66.0	71.5	1.70
PAfL / SL	70.3	71.7			69.6	74.0	1.60
DFBL / SL	55.0	54.0			51.6	56.2	1.74
DFL / SL	61.8	60.4			56.7	62.8	2.25
DFRL / SL	13.8	14.4			13.5	15.7	0.71
DFSL / SL	11.0	11.4			10.3	12.2	0.61
AFBL / SL	15.8	14.9			13.6	16.3	0.92
AFL / SL	20.9	22.8			21.6	24.1	0.84
AFSL / SL	11.9	12.5			11.4	14.2	1.03
AFRL / SL	13.1	15.2			14.0	16.5	0.96
PecL / SL	20.5	20.7			19.5	22.5	1.02
PelL / SL	21.0	21.9			20.5	22.7	0.70
PelSL / SL	9.4	10.4			9.3	11.0	0.56
PelRL / SL	19.9	20.1			18.7	21.5	1.01
CLLup / SL	25.2	25.5			23.3	26.6	1.13
CLLmid / SL	18.8	18.4			15.3	20.6	1.49