Syncomistes bonapartensis, 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 : 26-32

Syncomistes bonapartensis , new species

( Tables 9 , 10 , S 22 & S 23 ; Figures 8 & 9 )

Syncomistes butleri non Vari, 1978: 316: Paxton et al. 1989: 536 (in part); Allen & Leggett 1990: 538; Larson & Martin 1990: 55; Hutchins 2001: 31; Hutchins & Smith 1991: 22 (in part); Unmack 2001: 1063 (in part); Allen et al. 2002: 236 (in part); Moore et al. 2008: 24 (in part); Buckle et al. 2010: 17; Morgan et al. 2011a: 17 ; Larson et al. 2013: 162 (in part); Allen et al. 2017: online (in part).

Corresponds to the nominated taxa code ‘ S. butleri II’ of Shelley (2016).

English vernacular name: Lake Bonaparte Grunter.

Holotype (measured): NTM S.17646–003 (114 mm SL), Off Cossack Road, Katherine River , 14° 32' 52.8'' S, 132° 7' 48'' E. The holotype was obtained using gill nets by M. Hammer and party, October 1, 2012.

Paratypes (measured): 25 specimens, 45–269 mm SL. WAM P.34532.001 (2), 172–190 mm SL, Moonshine Gorge, Pentecost River , – 16° 2' 41.76'' S, 128° 0' 31.53'' E, June 8, 2013, obtained using gill nets in clear water over sandstone substrate by J. J. Shelley and M. C. Le Feuvre ; WAM P.34534.001 (1), 49 mm SL, Kuruntjie, Durack River , 16° 18' 10.33'' S, 127° 10' 44.15'' E, June 13, 2013, obtained using a fyke net in an isolated, turbid pool over sandy substrate by J. J. Shelley and M. C. Le Feuvre ; WAM P.34537.002 (1), 164 mm SL, Croc Hole, Wilson River, Ord River , 16° 38' 49.45'' S, 128° 6' 36.47'' E, July 10, 2013, obtained using gill nets in an isolated, turbid pool over sandstone substrate by J. J. Shelley and M. C. Le Feuvre ; NTM S.17648-008 (1), 45 mm SL, Old Victoria River Crossing , Victoria River, 15° 35' 2.4'' S, 131° 6' 7.2'' E, June 6, 2013, obtained using a backpack electrofisher by M. Hammer and party ; NTM S.17661-005 (1), 211 mm SL, Claravale, Daly River , 14° 21' 54'' S, 131° 33' 28.8'' E, September 27, 2013, obtained using a backpack electrofisher by M. Hammer and party ; NTM S.16347-001 (1), 129 mm SL, Sleisbeck Billabong, Katherine River, Daly River , 13° 48' 0'' S, 132° 51' 28.8'' E, August 9, 1988, collected by J. Bywater, method unknown ; NTM S.11616-003 (1), 80 mm SL, Reynolds River , 13° 10' 58.8'' S, 130° 34' 58.8'' E, September 1, 1984, obtained using combined methods by S. H. Midgley ; NTM S.15467-018 (3), 152–206 mm SL, Wickham River , Victoria River, 16° 51' 7.2'' S, 130° 13' 58.8'' E, June 1, 2002, obtained using gill nets by H.K. Larson and J. Papple ; NTM S.14549-001 (3), 131–197 mm SL, Finniss River , 13° 3' 36'' S, 130° 58' 33.6'' E, October 16, 1996, obtained using gill nets by J. Twining ; NTM S.16404-002 (1), 132 mm SL, Flying Fox Creek, Ord River , 16° 32' 54.26'' S, 128° 22' 13.31'' E, March 13, 2006, obtained using gill nets by D. Buckle and A. Storey ; NTM S.17646-003 (3), 88.2–175 mm SL, Off Cossack Road, Katherine River , 14° 32' 52.8'' S, 132° 7' 48'' E, October 10, 2012, collected using combined methods by M. Hammer and party ; NTM S.13299–001 (1), 269 mm SL, Kununurra, Lake Argyle, Ord River , 15° 49' 58.8'' S, 128° 43' 58.8'' E, collected in 1994 by Colin Ostle, methods unknown ; WAM P.34546.001 (3), 71.4–193 mm SL, Solea Falls Gorge, Drysdale River, 14° 38' 11.25'' S, 126° 58' 16.97'' E, July 10, 2014, obtained using gill nets in a deep pool with tannin stained water over sandstone substrate by J. J. Shelley and M. C. Le Feuvre ; WAM P.34545.001 (2), 138–142 mm SL, Miners Pool, Drysdale River , 15° 40' 49.33'' S, 126° 24' 23.67'' E, August 10, 2013, obtained using gill nets in a deep pool with tannin stained water over sandy substrate by J. J. Shelley and M. C. Le Feuvre ; WAM P.34528.001 (1), 140.7 mm SL, Carson R.– Morgan R. confluence, Carson River , King Edward River , 14° 44' 49.42'' S, 126° 46' 42.01'' E, August 3, 2012, obtained using gill nets in slow flowing run with clear water over soft sediment by J. J. Shelley and M. C. Le Feuvre.

Paratypes (not measured): 64 specimens, 35–212 mm SL. The following type material was obtained with rotenone by W. H. Butler, G. J. Nelson, and D. E. Rosen. AMNH 35644 (9), 57–78 mm, main stream of Bow River at Nicholson to Wyndham Highway crossing, (?) 16° 47' 36.74'' S, 128° 16' 47.59'' E, May 5, 1969 ; AMNH 35648 (11), 35–105 mm, main stream of Dunham River, one mi. downstream of old Nicholson to Wyndham Highway crossing, (?) 16° 9' 17.54" S, 128° 22' 6.02" E, May 6, 1969 ; AMNH 35650 (2), 121–139 mm, main stream of Ord River below dam at crossing of Great Northern Highway, (?) 15° 47' 25.25" S, 128° 41' 49.28" E, May 7, 1969 ; AMNH 35651 (10), 62–68 mm; WAM P-25390-001 (8), 62–69mm, West Baines River where crossed by Great Northern Highway, (?) 15° 45' 45.57" S, 130° 1' 44.49" E, May 8, 1969 ; AMNH 35649 (10), 28–212 mm; WAM P- 25387.001 (9), 57–211 mm, Katherine River, 8 mi. downstream from Katherine , (?) 14° 22' 58.99" S, 132° 21' 2.76" E, May 9, 1969 ; AMNH 35646 (3), 59–66 mm, Ferguson River where crossed by Katherine to Darwin ( Stuart ) Highway , (?) 14° 11' 0.07" S, 132° 2' 0.78" E, May 10, 1969 ; WAM P-25427-003 (1), Drysdale River , no date provided ; WAM P-21536 (1), Ord River, Stockyard Pools , (?) 15° 47' 48.07" S, 128° 42' 2.29" E, January 22, 1971, collected by R. J. McKay using unknown methods.

Diagnosis: A large species of the Syncomistes genus (recorded up to 280 mm SL, commonly 150–200 mm SL). Syncomistes bonapartensis sp. nov. differs from all other species within the Syncomistes complex by a combination of the following characters: lower jaw rounded anteriorly making a ‘U-shape’ when viewed from below, in juveniles and adults ( Fig. 5a ); mouth slightly oblique; teeth broad and large relative to Syncomistes , flat, asymmetric, margins convex posteriorly and straight to slightly concave anteriorly, widest point closest to midpoint of tooth, apical region tapered to slight point ( Fig. 6a ): body often with 7–8 slightly wavy brown stripes running horizontally along sides; usually <11 gill rakers on the upper arch and <30 in total; usually ≥ 6.0 teeth per mm of jaw; distributed between the Finnis River in the Northern Territory and the King Edward River that drains the northern Kimberley Plateau.

Description: See Table 9 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 (XI–XIII), rays 12 (12–13); anal fin spines III, rays 9 (8–10); caudal fin rays 10+8+7+9 (9–10+8+7+9, n = 3); pectoral fin rays 16 (15–17); pelvic fin spines I, rays 5; vertebrae 11+14 = 25 (n = 3); lateral line scales 50 (47–51); scales above lateral line 11 (9–12); scales below lateral line 19 (17–21); pre-dorsal fin scales 18 (14–25); cheek scale rows 5 (4–6); caudal peduncle scales 30 (26–32); gill rakers on first arch 9+18 = 28 (7–10 + 16–20 = 23–30); opercular spines 2 (2–3); preopercular spines 22 (19–41).

See Table 10 for a summary of morphometric variation by type material and other material examined and Table S23 morphometric variation across all specimens combined. Dorsal profile steep: straight, convex, or slightly concave from tip of snout to occiput, slightly concave at occiput, convex or straight from occiput to dorsal fin origin, and convex behind dorsal fin origin to base of last dorsal ray, then horizontal to caudal fin base. Ventral profile slightly convex and downward angled on underside of head, convex from pelvic fin origin to below last dorsal fin ray, and horizontal to caudal fin base. Lateral line continuous from behind head to base of caudal fin, and approximately parallel with dorsal profile. Body depth at dorsal fin origin 36.6 (32.6–44.7) % SL; body depth at anal fin origin 32.7 (28.5–44.3) % SL; caudal peduncle length 16.6 (14.7–18.4) % SL; caudal peduncle depth 12.3 (11.3–14.0) % SL; pre-anus length 67 (62.2–72.3) % SL. Head length 29.6 (23.8–33.5) % SL; head pointed; snout length 39.8 (33.7–43.0) % HL; upper-jaw length 30.3 (26.4–33.9) % HL; jaws equal throughout development; jaw width 30.9 (23.8–35.0) % HL. Mouth terminal, horizontal or slightly angled upwards in lateral profile. Outer row of large teeth of same size with 2–4 rows of smaller teeth on both jaws, embedded in a jelly-like gum; tooth size decreasing from outer row to inner rows. Teeth on outer row of upper jaw 59 (31–79), number varying with size, 6 (3.8–7.3) / mm when standardised with upper jaw length; 4 (3–4) teeth rows behind outer row; teeth on outer row of lower jaw 55 (28–72), number varying with size, 4.5 (3.1–7.4) / mm when standardised with upper jaw length; 3 (2–3) tooth rows behind outer row. Teeth laterally compressed, broad and large relative to Syncomistes , asymmetric shape, margins convex posteriorly and straight to slightly concave anteriorly, widest point closest to mid-point of tooth, apical region tapered to slight point, teeth fitted close together with some overlap (Tooth Morphotype 1; Fig. 6a ), laterally pointed in lower jaw, but not extending beyond outer lip. Toothless medial hump present on dorsal surface at symphysis of lower jaw, opposite toothless region of upper jaw in some specimens. Lower jaw U-shaped in juveniles and adults when viewed from below (Morphotype 1; Fig. 5a ). Upper jaw usually with fleshy, narrow, lip fold that is mostly discontinuous across the ventral midline, but occasionally continuous. Orbital diameter 21.4 (16.6–28.7) % HL; inter-orbital width 33.7 (26.8–38.2) % HL; post-orbital length 42.2 (40.2–46.8) % HL. Interorbital smooth, with bony ridge above each orbit. Parietal and supracleithrum sometimes serrated. Lower opercular spine longer and more robust than upper opercular spine, sometimes extending beyond edge of opercular membrane; preopercular spines serrate, longest and most robust on apex of preopercle, reduced in size dorsally and anteriorly, anteriormost spine situated behind 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 rows 3 (2–3) anteriorly, increasing posteriorly; 5th (5th–8th) dorsal spine longest, length 15.7 (13.2–18.6) % SL; spines progressively shorter from first and last respectively; last dorsal fin spine fully linked to first dorsal fin ray by membrane; 2nd (1st–4th) dorsal ray longest, length 15.7 (13.5– 17.7) % SL; margin of rayed portion rounded to tip of last ray; dorsal fin base length 56.2 (48.6–63.0) % SL; dorsal fin length 62.7 (55.6–68.7) % SL; pre-dorsal fin length 39.7 (34.7–43.1) % 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 3 (2–5) anteriorly, increasing posteriorly; 2nd anal spine longest, length 17.9 (14.5–22.7) % SL; 1st (1st–2nd) anal ray longest, length 16.9 (13.8–19.3) % SL; subsequent rays progressively shorter; distal margin of rayed portion rounded; anal fin base length 17.6 (14.7–19.5) % SL; anal fin length 24.4 (22.7–26.8) % SL; pre-anus length 67 (62.2–72.3) % SL. Caudal fin slightly emarginate in juveniles, emarginate in adults; upper caudal lobe length 29 (23.0–34.4) % SL; middle caudal ray 18.4 (16.5–23.0) % SL. Pectoral fin length 20 (17.3–22.2) % SL; pre-pectoral fin length 28.7 (22.9–32.2) % SL. Pelvic spine length 12.9 (10.4–15.9) % SL; 1st (1st–2nd) pelvic ray longest, length 21.8 (18.6–24.7) % SL; pelvic fin length 23.1 (19.4–27.2) % SL; pre-pelvic fin length 38.9 (35.4–43.2) % SL.

Colour when fresh: Overall colouration of adults uniformly silver, iridescent olive green to blue, or light grey. Occasionally with 7–8 longitudinal body stripes on juveniles and adults, that quickly fade when removed from the water or after death: first running along sheath at base of spinous dorsal from third dorsal spine to third or fourth ray; second, from origin of dorsal to below soft dorsal; third, from above eye across post-temporal and then to just beyond based on last soft dorsal ray; fourth, from upper opercular spine to dorsal edge of caudal peduncle; fifth stripe widest, from back of eye across opercle to caudal fin base; sixth, from largest opercular spine to ventral edge of caudal peduncle; seventh stripe wavy, running from dorsal edge of pectoral base to rear of soft anal fin; eighth indistinct and sometimes lacking, positioned below seventh stripe from ventral edge of pectoral fin base to base of anal fin spines.

Colour when preserved: Juveniles and adults uniformly dark brown to grey with hints of pale colouration becoming more dominant towards the ventral region. Mostly pale brown when viewed ventrally. All fins slight to dark brown. Lateral line is distinctly pale in colouration. Overall colouration fades from darker to lighter the longer the specimen is preserved.

Distribution: See Fig. 9 . Found throughout all surveyed catchments from the Drysdale River in the northern Kimberley (Western Australia) to the Finnis River (Northern Territory). A number of rivers remain unsurveyed within its range (notably the Berkley and Forrest rivers) where its presence has not been confirmed.

Ecology: Prefers deeper sections of slow-flowing creeks and rivers, as well as billabongs. Found in clear and turbid waters, over muddy to rocky substrates, often where algae is abundant. Have been recorded in water temperature up to 36°C. Adults form shoals around snags. Juveniles predominantly reside in riffle habitat. Individuals sexually mature at 120–140 mm and breed during the wet season. Eggs are large (~ 3 mm) and nonadhesive. Diet primarily consists of filamentous algae along with some detritus and invertebrates.

Comparison: Syncomistes bonapartensis , along with S. butleri , is very different to other species in the genus. Its distinctive features include a terminal mouth, a wide, rounded U-shaped jaw when viewed from below, and a thick, fleshy lip fold on the upper and lower lip and a deeper body at the dorsal fin origin 36.6 (32.6–44.7) % SL and at the anal fin origin 32.7 (28.5–44.3) % SL, and a distinctively steep ventral profile that is straight or concave in adults and slightly convex in juveniles.

Very similar in appearance to S. butleri , however it has fewer gill rakers on the upper arch 9 (7–10) versus 11 (8–12), and 27 (26–30) versus 31 (27–32) in total, has more teeth in relation to jaw length 6.0 (3.8–7.3) versus 4.0 (3.1–7.4), has a shorter head length 29.6 (23.8–33.5) % SL versus 31.5 (28.3–33.5) % SL, and a smaller orbital diameter 21.4 (16.6–28.7) % HL versus 23.3 (17.3–29.2) % HL.

Colouration is much the same as in S. butleri , but with 7–8 rather than 5–6 horizontal body stripes when they are present. This character is particularly useful in distinguishing juvenile specimens, as stripes are most often present.

Etymology: The specific name bonapartensis refers to the distribution of the species that is confined to drainages that once flowed into the paleolake, Lake Bonaparte.

Remarks:. Based on broad scale genetic analysis, and morphological examination of some of the original paratype series for S. butleri s.s., the distribution boundary between the two species is between the Finnis River and Adelaide rivers in the Northern Territory. Consequently, the specimens from all rivers west of the Finnis River that were included in the original S. butleri s.l. paratype series are considered to be S. bonapartensis . This species is found in sympatry with S. holsworthi , S. kimberleyensis , S. rastellus and S. trigonicus .

Figures

FIGURE 5.

FIGURE 6.

FIGURE 8.

FIGURE 9.

Tables

TABLE 9.Summary of meristic variation in Syncomistes bonapartensis sp.nov. (values for numberof teeth of upper and lower jaw are per mm of jaw length).

	Holotype	Paratypes (N = 26)
Character		Mode	Mean	Min.	Max.	S.D.
DS	12	12	12.0	11.0	13.0	0.35
DR	13	12	12.4	12.0	13.0	0.50
AS	3	3	3.0	3.0	3.0	0.00
AR	10	9	9.0	8.0	10.0	0.54
PecR	16	16	16.1	15.0	17.0	0.57
PelS	1	1	1.0	1.0	1.0	0.00
PelR	5	5	5.0	5.0	5.0	0.00
UUCR	10	10	9.5	9	10	0.58
UBCR	8	8	8	8	8	0.00
LBCR	7	7	7	7	7	0.00
LUCR	9	9	9	9	9	0.00
LLSc	50	50	50.1	47.0	51.0	1.04
LD	11	11	10.6	9.0	12.0	0.76
LA	20	19	18.8	17.0	21.0	0.97
PDSc	19	18	18.0	14.0	25.0	2.27
DSSc	3	2	2.4	2.0	3.0	0.49
ASSc	3	3	3.3	2.0	5.0	0.61
CScR	5	5	4.6	4.0	6.0	0.64
CPSc	30	30	29.4	26.0	32.0	2.06
GRup	9	9	8.8	7.0	10.0	0.80
GRlow	19	18	18.4	16.0	20.0	0.92
GRtot	28	27	27.3	26.0	30.0	0.98
PcV	11	11	11	11	11	11
CV	14	14	14	14	14	14
TV	25	25	25	25	25	25
LDR	2	2	2.4	1.0	4.0	0.65
LDS	5	6	6.1	5.0	8.0	0.86
LAR	1	1	1.2	1.0	2.0	0.41
LAS	2	2	2.0	2.0	2.0	0.00
LPR	1	1	1.1	1.0	2.0	0.33
Tup	5.5	4	4.8	3.4	8.2	1.21
Tlow	5.1	4	4.5	3.1	7.4	1.13
TRup	3	4	3.6	3.0	4.0	0.51
TRlow	3	3	3.3	3.0	4.0	0.44
OS	2	2	2.0	2.0	2.0	0.00
PS	22	23	22.5	13.0	40.0	6.49

TABLE 10. Morphometric variation in Syncomistes bonapartensis sp. nov. (values are percentages of denominators in ratios, except for SL).

	Holotype	Paratypes (N = 26)
Character		Mean	Min.	Max.	S.D.
SL (mm)	114	147.8	45.0	269.0
BDd / SL	34.7	36.7	32.6	44.7	2.73
BDa / SL	30.5	32.8	28.5	44.3	3.05
CPL / SL	15.6	16.6	14.7	18.4	0.94
CPD / SL	11.4	12.3	11.3	14.0	0.63
HL / SL	31.0	29.5	23.8	33.5	1.99
OD / HL	21.3	21.4	16.6	28.7	2.96
IoW / HL	34.1	33.6	26.8	39.2	2.74
PoL / HL	40.9	42.2	40.2	46.8	1.32
SnL / HL	41.0	39.8	33.7	43.0	1.94
JLup / HL	30.4	30.3	26.4	33.8	1.88
JW / HL	27.0	31.1	23.8	35.0	2.99
PDFL / SL	39.6	39.7	34.7	43.1	1.83
PPecL / SL	30.2	28.6	22.9	32.2	2.25
PPelL / SL	38.6	38.9	35.4	43.2	1.98
PAL / SL	65.4	67.0	62.2	72.3	2.26
PAfL / SL	71.0	71.9	67.6	76.6	2.34
DFBL / SL	53.7	56.3	48.6	63.0	2.80
DFL / SL	60.3	62.8	55.6	68.7	2.82
DFRL / SL	15.6	15.7	13.5	17.7	1.22
DFSL / SL	15.9	15.7	13.2	18.6	1.39
AFBL / SL	18.2	17.6	14.7	19.5	1.18
AFL / SL	24.3	24.4	22.7	26.8	1.09
AFSL / SL	18.7	17.9	14.5	22.7	1.81
AFRL / SL	16.9	16.9	13.8	19.3	1.40
PecL / SL	18.6	20.1	17.3	22.2	1.34
PelL / SL	20.9	23.2	19.4	27.2	1.61
PelSL / SL	12.4	12.9	10.4	15.9	1.33
PelRL / SL	19.7	21.8	18.6	24.7	1.54
CLLup / SL	26.8	29.1	23.0	34.4	2.56
CLLmid / SL	17.0	18.4	16.5	23.0	1.41