Difference between revisions of "Helcogramma williamsi"

Latest revision as of 16:21, 21 August 2012

Taxonavigation

Ordo: Perciformes
Familia: Tripterygiidae
Genus: Helcogramma

Name

Helcogramma williamsi Chiang & Chen, 2012 sp. n. – Wikispecies link – ZooBank link – Pensoft Profile

Holotype

NTOU-P 2012-02-002, male, 27.5 mm SL, Feng-chui-sha, Hengchun Township, Pingtung County, Taiwan, 1-3 m depth, M. C. Chiang and J. H. Huang, 3 June 2008.

Paratypes

5 paratypes were collected with holotype: NTOU-P 2012-02-001, male, 29.0 mm SL; NTOU-P 2012-02-003, male, 25.4 mm SL; NTOU-P 2012-02-004, female, 28.5 mm SL; NTOU-P 2012-02-005, 2 females, 21.1 and 21.3 mm SL.

Diagnosis

The new species can be distinguished from congeners by the following combination of features. Second dorsal-fin spines XIII; third dorsal-fin rays modally 11; anal-fin rays modally 19; lateral line with 22-24 pored scales; pattern of dentary pores modally 5+1+5; nape naked; supraorbital cirrus lobate; nasal cirrus broad, serrated or palmate; first dorsal fin lower in height than second; males with yellow mark from anterior tip of upper lip to anterior margin of eye and a whitish blue line extending from corner of mouth onto preopercle.

Description

D III, XIII-XIV (holotype: XIII), 10-11 (holotype: 11). A I, 19-20 (holotype: 19). Pectoral fin rays 1+8+7, uppermost ray simple, eight middle rays branched, seven lowermost rays simple. Pelvic fin I, 2, rays united by membrane for half the length of shorter ray. Caudal fin rays 2+9+2, two uppermost and lowermost rays simple, nine middle rays branched. Scale rows 36-37. Lateral line with 22-24 (holotype: 24) pored scales, ending below 2nd-4th ray of third dorsal fin. Patterns of cephalic sensory canal pores are illustrated in Fig. 2. Dentary with a single symphyseal pore, dentary pore pattern 5-6+1+5-6 (holotype: 5+1+5). Vertebrae 10+26. No free pterygiophore between second and third dorsal fins.
Body moderately elongate and compressed. Head moderately large, dorsal profile triangular. Body covered with ctenoid scales. Head, nape, base of pectoral fin, and abdomen naked; body scales not extending to bases of first and anterior portion of second dorsal fins. Mouth terminal, posteriormost margin of maxilla just reaching vertical through anterior margin of pupil. Eye moderately large and slightly angled dorsally. Supraorbital cirrus lobate, usually with micromelanophores. Anterior nostril a short tube with broad, serrated or palmate nasal cirrus. First dorsal fin lower in height than second in both sexes. Anal fin beginning below vertical through base of 7th or 8th spine of second dorsal fin; pectoral fin large and pointed, posterior tip of longest ray below last spine of second dorsal fin; caudal fin truncate to slightly rounded. Morphometric data are listed in Table 1. {| class="wikitable" ; style="width: 100%" |+ Table 1. Measurements of type specimens of Helcogramma williamsi, sp. n.,from Taiwan. |- ! Type status !! Holotype !! All type specimens (n = 6) |- | Standard length (mm) || 27.5 || 21.1 – 29.0 || |- | In % of standard length |- | Head length || 29.1 || 28.4 – 29.5 || ( 28.9 ) |- | Body depth of anal fin origin || 18.2 || 16.6 – 18.2 || ( 17.4 ) |- | Body width of anal fin origin || 14.5 || 12.3 – 14.5 || ( 13.3 ) |- | Head width in maximum || 24.7 || 23.0 – 24.9 || ( 24.1 ) |- | Predorsal(1) length || 26.2 || 25.2 – 27.2 || ( 26.1 ) |- | Predorsal(2) length || 37.1 || 34.0 – 38.5 || ( 36.0 ) |- | Predorsal(3) length || 70.2 || 68.4 – 71.8 || ( 70.2 ) |- | Prepectoral-fin length || 32.0 || 32.0 – 33.8 || ( 33.0 ) |- | Prepelvic-fin length || 23.6 || 22.1 – 26.8 || ( 23.7 ) |- | Preanal-fin length || 48.7 || 48.7 – 52.6 || ( 50.4 ) |- | Caudal-peduncle length || 10.2 || 8.5 – 10.2 || ( 9.4 ) |- | Caudal-peduncle depth || 8.7 || 8.0 – 9.1 || ( 8.5 ) |- | Pectoral-fin length || 33.8 || 29.0 – 35.7 || ( 32.8 ) |- | Pelvic-fin length || 21.1 || 20.4 – 21.1 || ( 20.8 ) |- | Caudal-fin length || 20.7 || 20.3 – 23.0 || ( 21.2 ) |- | D1 fin base || 11.3 || 9.8 – 11.7 || ( 10.7 ) |- | D2 fin base || 34.9 || 34.3 – 36.2 || ( 35.0 ) |- | D3 fin base || 19.6 || 19.3 – 20.4 || ( 19.9 ) |- | A fin base || 43.6 || 41.1 – 45.3 || ( 43.1 ) |- | D1 1st spine length || 9.8 || 8.4 – 9.8 || ( 9.3 ) |- | D2 1st spine length || 12.0 || 11.6 – 13.1 || ( 12.3 ) |- | Head length (mm) || 8.0 || 6.0 – 8.5 || |- | In % of head length |- | Head width in maximum || 85.0 || 78.8 – 89.3 || ( 84.4 ) |- | Eye diameter || 30.0 || 28.0 – 33.3 || ( 30.5 ) |- | Interorbital width || 8.8 || 8.2 – 9.9 || ( 9.0 ) |- | Upper-jaw length || 43.8 || 41.0 – 43.8 || ( 42.4 ) |- | Snout length || 35.0 || 34.4 – 36.5 || ( 35.0 ) |- | Eye diameter (mm) || 2.4 || 2.0 – 2.5 || |- | In % of eye diameter |- | Nasal tentacle length || 12.5 || 12.0 – 16.7 || 14.2 |- | Orbital tentacle length || 16.7 || 15.0 – 20.0 || 17.9 |}

Colouration when fresh

Males with top of head orange red; lower half of head below eyes, inclusive of lips and branchiostegal membranes, covered with scattered melanophores on pale gray background; opercle heavily spotted and mostly dusky. A whitish blue line extending from posterior flange of maxilla across cheek onto preopercle; faint orange spots below eye and along sides of mouth. Iris orange to red. Snout with iridescent yellow mark, bordered ventroposteriorly by dusky line from anterior margin of eye to anterior tip of upper lip. Body mottled yellow and orange on dorsum; pairs of orange or red, indistinct, slightly angled semi-bars from behind pectoral-fin base to caudal fin, last half-pair forming triangular mark on caudal peduncle. Mid-lateral series of reddish brown blotches, elongating into slender dorsal bars, with intervening white spots. Pectoral-fin base with yellowish white splotch centrally, red and white marks ventrally; pectoral fins dusky with irregular dark and pale bars. Pelvic fins mostly white, pink or pale orange basally. Dorsal fin dusky to black along distal margins of all membranes; first dorsal fin speckled with yellow and black on membrane between first two spines; second and third dorsal fins diagonally striped with faint reddish or dusky markings, markings roughly in line with semi-bars, those on side of body. Anal fin dusky red. Caudal fin dusky.
Females with head reddish above, dark brown behind centre of eye and onto upper portion of opercle; ventral half of head pale cream below eye, with some black and orange spots. Iris red to reddish brown. Snout with brownish black line from anterior margin of eye onto upper lip. Body pale pink, sides of body with orange and red marks forming pairs of discontinuous semi-bars and blotches, from dorsum to below lateral midline, last half-pair forming triangular mark on caudal peduncle; a row of white spots along mid-body between each dark blotch. Pectoral-fin base with a white splotch at lower edge, which seems to extend form white marking on lower portion of opercle, and red and white marks above; fin rays with alternating white and black bars. Pelvic fin white. First dorsal fin as in males; second dorsal fin diagonally striped with red markings; third dorsal fin banded with dusky red and white oblique bands. Anal fin with dusky red blotches along base. Caudal fin dusky, melanophores concentrated along outlines of ray shafts, interspaced with two white, vertical bars.

Colouration in preservative

Males with head and body dusky, except belly and area behind eye clear. Body dusky with irregular double bars. Pectoral fins dusky with clear blotches on upper and lower margins of base. Distal halves of first and second dorsal fins dusky, membrane between first two spines of first dorsal with dense melanophores; third dorsal fin irregularly banded. Anal and caudal fins dusky.
Females generally pale to dusky. Top of head, opercle and pectoral-fin base with scattered melanophores; small clusters of melanophores below eye and along sides of mouth; a dusky bar of melanophores extending from eye onto upper lip. Body with faint, barely discernible, irregular markings. First dorsal fin as in males; second dorsal fin with clusters of melanophores near distal margin. Pectoral, third dorsal and caudal fins banded, melanophores concentrated along margins of fin elements. Anal fin with blotches of melanophores basally.

Etymology

The specific name, williamsi, is in honor of Jeffrey T. Williams, Smithsonian Institution, National Museum of Natural History, in recognition of his excellent research work on marine blenniiform fishes.

Distribution

The samples were collected from rocky shore areas with sand channels at depths of 1-3 m, along the southern coast of Taiwan.

Remarks

Helcogramma williamsi shares the pattern of dentary pores and the numbers of fin rays and lateral-line scales with three congeners: Helcogramma capidata Rosenblatt (1960)^[1], Helcogramma alkamr Holleman (2007)^[2], and Helcogramma rharhabe Holleman (2007)^[2].These four species, as well as others in the Helcogramma obtusirostris species group, also share a putative synapomorphy- a blue line running from the corner of the mouth onto the preopercle in mature males.
However, Helcogramma williamsi is distinguished from Helcogramma capidata by its lobate supraorbital cirrus vs. without supraorbital cirrus; upper jaw extending to a point below anterior half of eye vs. extending to a point below posterior half of eye; and moderately complex cephalic sensory canal pores vs. rather simple pore pattern. Helcogramma williamsi can bedistinguished from Helcogramma rharhabe by the following features: vertebrae 10+26 vs. 10+24-25; males with yellow mark from anterior tip of upper lip to anterior margin of eye vs. crimson marks on upper lip on either side of center, black in the centre; body with 5-6 pairs of indistinct semi-bars vs. body of males almost entirely black with 3-4 pale narrow streaks from dorsum to midline. Helcogramma williamsi seems to be more similar to Helcogramma alkamr than to any other congeneric species in overall pattern of colouration. However, it can be distinguished from Helcogramma alkamr by the following features: height of first dorsal fin more than half height of second dorsal fin vs. height of first dorsal fin less than half height of second dorsal fin; lateral-line scales extending to a point below insertion between 2nd-4th rays of third dorsal fin vs. lateral-line scales extending to a point just below the junction of second and third dorsal fins; ventral side of caudal peduncle with cycloid scales vs. ventral side naked; iris orange-red with reddish brown ring vs. red and pale gold.

Original Description

• Chiang, M; Chen, I; 2012: A new species of the genus Helcogramma (Blenniiformes, Tripterygiidae) from Taiwan ZooKeys, 216: 57-72. doi

Other References

1. ↑ Rosenblatt R (1960) The Atlantic species of the blennioid fish genus Enneanectes. Proceedings of the Academy of Natural Sciences of Philadelphia 112: 1-23.
2. ↑ ^{2.0 2.1} Holleman W (2007) Fishes of the genus Helcogramma (Blennioidei: Tripterygiidae) in the Western Indian Ocean, Including Sri Lanka, with descriptions of four new species. Smithiana Bulletin 7: 51-81.

Images

Figure 1. Helcogramma williamsi sp. n., Feng-chui-sha, Pingtung, Taiwan a Holotype, NTOU-P 2012-02-002, male, 27.5 mm SL b Paratype, NTOU-P 2012-02-005, female, 21.3 mm SL.  Figure 2. Cephalic sensory canal system of Helcogramma williamsi sp. n., holotype, NTOU-P 201202-002, male, 27.5 mm SL a Dorsal view b Lateral view c Ventral view. Canal system indicated in gray. Scale bar = 1 mm.