Oryzias hadiatyae, Herder & Chapuis, 2010

Herder, Fabian & Chapuis, Simone, 2010, Oryzias Hadiatyae, A New Species Of Ricefish (Atherinomorpha: Beloniformes: Adrianichthyidae) Endemic To Lake Masapi, Central Sulawesi, Indonesia, Raffles Bulletin of Zoology 58 (2), pp. 269-280 : 271-275

Oryzias hadiatyae , new species

(English common name: Renny’s ricefish) ( Figs 3 , 4 ; Table 1)

Material examined. – Holotype - MZB 18491 (34.2 mm SL), male, Indonesia, Sulawesi: South Sulawesi Province; Larona drainage; Lake Masapi , southern shore between 2°50.837'S 121°21.116'E and the lake’s outlet, approx. 600 m westwards of this position; F. Herder, J. Pfaender, J. Schwarzer & R. K. Hadiaty 15–16 Apr.2004.

Paratypes – All collected with the holotype: MZB 18492–18506 , 4 males (22.5–30.3 mm SL), 11 females (23–44.6 mm SL), ZFMK 41540–41550 , 4 males (31.6–40.3 mm SL), 7 females (32–43.2 mm SL), ZSM 39760–39766 , 2 males (28.4 & 31.6 mm SL), 5 females (34.5–43.7 mm SL), ZRC 51984, 2 males (28 & 29.7 mm SL), 2 females (29.3 & 46.1 mm SL) .

Diagnosis. – Oryzias hadiatyae is distinguished from all other Adrianichthyidae in Sulawesi by combination of a well marked concavity on the snout ( Fig. 5 ), a slightly upwards directed mouth, a slender but relatively wide body (body depth 18.2–25.7% SL, body width 10.9–14.5% SL), pelvic fins with 5–6 fin rays inserting relatively close to the rear end of the body (prepelvic length>47.7% SL), anal fin with 19–22 fin rays inserting relatively close to the rear end of the body (preanal length>63% SL), dorsal fin with 8–10 rays inserted above 10–12 th anal fin ray, 28-30 vertebrae, large eyes (30–39.8% HL), 27–31 lateral scales, ½ 10–14 transversal scale rows, absence of dark blackish, dark bluish, or steel blue body colouration or brilliant red marks in both sexes, presence of dark brown blotches on the lateral body in adult males, and absence of these blotches in females.

Comparisons. – Compared to other lacustrine Adrianichthyidae from Sulawesi, O. hadiatyae is characterized by having conspicuously few large, lateral scales [27–31 vs.> 62 in Adrianichthys (including “ Xenopoecilus ” oophorus and “ X.” poptae ; see Parenti, 2008),> 40 in O. orthognathus , and 32–34 in O. profundicola , 36–39 in O. bonneorum , 32–36 in O. nebulosus , 34–37 in O. nigrimas ,> 44 in O. orthognathus , 70–75 in O. sarasinorum (see Kottelat 1990b; Parenti, 2008)]. In addition to non-overlapping lateral scale counts, O. hadiatyae is distinguished from O. orthognathus in L. Poso, sharing a similar concavity on the snout, by having a deeper caudal peduncle (1.1–1.6 vs. 1.7–1.9 times longer than deep), larger eyes (8.8–14% SL vs. 7.6–8.7% SL), a longer snout (8.2–11.8% SL vs. 7–8% SL), the dorsal fin inserted less anterior (origin above 10–12 th vs. 13–16 th anal ray), a smaller size (up to 46.1 mm SL vs. 51.5 mm SL), less anal fin rays (19–22 vs. 23–25) and only 5–6 (vs. 7) pelvic fin rays; the last pelvic ray is connected to the body by a membrane on half to whole length in females and to half length in males, vs. not connected in O. orthognathus ( Kottelat, 1990b; Parenti, 2008). Lateral scale counts overlap with O. marmoratus (having 31–32 lateral scales), which are however arranged in ½ 13–15 (vs. ½ 10–14 in O. hadiatyae ) transversal rows (see also Kottelat, 1990a).

In contrast to other lacustrine Oryzias from L. Poso and the Malili Lakes, the origin of anal and pelvic fins is conspicuously far from the caudal fin base in O. hadiatyae and can be used to clearly distinguish the species (preanal length: 63.3–83.6% SL vs. <63% SL in O. nebulosus , O. nigrimas , O. orthognathus , O. matanensis , O. marmoratus and O. profundicola ; prepelvic length:>47.7% SL vs. <47.7% SL in O. orthognathus , O. profundicola and O. marmoratus ). Oryzias nigrimas and O. matanensis can, like O. orthognathus , be distinguished from O. hadiatyae by their more posterior position of the dorsal fin origin relative to the anal fin origin (dorsal fin origin above the>12 th anal ray in contrast to the 10–12 th anal ray in O. hadiatyae ). Adult male O. hadiatyae do not show dark blackish or bluish body colouration as in males of O. nigrimas or O. nebulosus ; both species have moreover a shorter snout than O. hadiatyae (8.2–11.8% SL vs. 6–8% SL in O. nebulosus and O. nigrimas ). Oryzias hadiatyae has fewer anal fin rays than O. orthognathus , O. profundicola , A. kruyti , A. poptae and A. roseni (19–22 vs.>22; Kottelat, 1990a, 1990b; Parenti & Soeroto, 2004), and a relatively shorter caudal peduncle compared to O. orthognathus . Compared to A. kruyti , A. poptae , A. roseni and O. sarasinorum , O. hadiatyae has less (8–10 vs.>10) rays in dorsal fin. Likewise, it is distinguished from O. bonneorum by having fewer dorsal fin rays (12–13 in O. bonneorum ) and relatively larger eyes (8.8–14% SL vs. 9–10% SL). It differs from O. celebensis in head shape ( Fig. 5 ), reflected by higher relative snout length (8.2–11.8% SL vs. 5.7–8.1% SL) and

Holotype MZB Paratypes (males, n=12) Paratypes (females, n=25)

18491 Min. Max. Mode Min. Max. Mode

Standard length (mm) 34.2 22.5 40.3 23 46.1

Anal fin rays (total) 20 19 22 19/21 19 22 20

Dorsal fin rays (total) 9 8 10 9 8 10 9

Pelvic fin rays 6 5 6 6 6 6 6

Pectoral fin rays 11 10 11 10 10 11 10

Caudal fin rays (total) 3/2/4+5/2/3 3/2/4+5/2/3 3/2/4+5/2/3 3/2/4+5/2/3 3/2/4+5/2/3 3/2/4+5/2/3 3/2/4+5/2/4

Scales in lateral row 29 28 31 28 27 31 28

Scales in transverse row 12 11 13 13 10 14 11

Vertebrae 28 28 29 29 28 30 29

% Standard length Min. Max. Mean SD(±) Min. Max. Mean SD(±) Total length 127.3 126.9 131.4 129 1.5 123.9 163.7 129.5 7.25 Head length 28 27.2 29.7 28.8 0.8 27.6 37.1 29.8 1.70 Head depth 14 13.5 15.1 14.1 0.6 13.5 19.4 15.3 1.23 Head width 13.5 15.1 16.8 16 0.5 15.7 19.9 16.5 0.80 Predorsal length 77.4 75.7 79.3 77.9 1.1 76.2 100.7 79.5 4.67 Prepelvic length 53.3 47.8 56.3 52.3 2.2 48.7 67.6 54.3 3.22 Preanal length 65.9 63.4 68.3 65.8 1.7 63.3 83.6 66.3 3.88 Body depth 23.8 18.2 22.6 20 1.2 19.3 25.7 20.8 1.33 Body width 12.7 10.9 14.4 12.4 1.1 12.4 14.5 13.4 0.58 Length of caudal peduncle 11.7 9.7 12.9 11.6 0.8 9.5 13.4 11.5 0.92 Depth of caudal peduncle 8.9 7.5 9.7 8.4 0.6 7.5 10.5 8.5 0.65 Length of dorsal fin 29.6 21.1 31.1 27.8 3.3 14.5 20.2 16.6 19 Length of dorsal fin base 10 7.8 11.1 9.9 0.9 8.1 11.7 9.8 0.78 Length of anal fin base 27.3 24.4 27.8 26.7 0.9 24.2 34.9 26.2 2.14 Length of pectoral fin 23.4 20 23.3 21.7 1.2 17.5 27.1 20.8 1.77 Length of pectoral fin base 6.3 5.3 6.9 5.9 0.4 5.1 7.9 6 0.57 Length of pelvic fin 11.9 10.2 12.5 11.5 0.7 9.8 15.4 12 1.28 Length of pelvic fin base 1.9 1.4 2.4 1.9 0.4 1.4 2.7 2 0.30

% Head length

Interorbital width 30.1 23.8 35.8 31.1 3.9 21.9 39.3 32.3 4.39 Eye diameter 35.6 35.5 39.8 37.5 1.6 30 39.8 33.5 2.12 Snout lenght 33 30.4 35 31.6 1.4 27.8 36.3 31.9 27

higher relative head length (27.2–37.1% SL vs. 22.7–28.5% SL). Furthermore, it does not show the pattern of stripes on the posterior flank and on caudal fin characteristic for O. celebensis ( Parenti, 2008; Kottelat et al., 1993), but has a faint black lateral stripe along lateral line. Oryzias hadiatyae is distinguished from O. woworae by colour pattern, most conspicuously the absence of steel blue body colouration and of brilliant red colouration in ventral surface of head and body anterior to pelvic fins, dorsal portion of pectoral fins, bases of dorsal and anal fin, and margins of caudal fin in both sexes, vs. presence of dark brown blotches on the lateral body in adult males, and absence of these blotches in females. Oryzias hadiatyae grows larger than O. woworae (SL up to 46.1 mm vs. 28 mm), and is characterized by the concavity on its more prominent snout (vs. dorsal surface of head slightly convex; relative snout length 8.2–11.8% SL vs. 6–8% SL; Parenti & Hadiaty 2010).

Besides meristic differences, head shape and colouration, O. hadiatyae differs from the Malili Lakes Oryzias by its more slender body [body depth 18.2–25.7% SL vs. 24.7–31.8% SL ( Kottelat, 1990a) / 26–30.72% SL (present study; Appendices 1, 2) in O. marmoratus , 26–31% SL ( Kottelat, 1990a) / 24.8–28.6 (present study) in O. matanensis , 30.4–35.2% SL in O. profundicola ( Kottelat, 1990a) / 28.3–39.1% SL in O. profundicola / O. marmoratus (present study)], and laterally wider body [body width 10.9–14.5% SL vs. 10.5–13.5% in O. matanensis , 9.3–12.5% in O. profundicola , and 8.4–11% in O. marmoratus ( Kottelat 1990a) ]. Oryzias hadiatyae has a more slender caudal peduncle than O. matanensis (depth 7.5–10.5% vs. 10.6–12.8% SL), O. profundicola (10.6–13% SL) and, with some overlap, also than O. marmoratus (9.8–11.9% SL). In addition to meristic and morphometric characters, O. hadiatyae differs from O. matanensis in fin colouration (life: male dorsal and anal fin blackish brown, with a narrow blackish margin in anal fin, vs. male dorsal and anal fin blackish; preserved: dorsal and anal fin dusky grey hyaline to light brown with narrow blackish anal fin margin, vs. dusky blackish with hyaline margins), body colouration with small irregular blackish blotches or spots scattered around axial stripe in males and no blotches or spots in females, vs. a row of black vertical elongate blotches along axial stripe plus several smaller black blotches distributed irregularly on lateral body (blackish pigmentation most conspicuous in males) in O. matanensis . In terms of meristics and morphometrics, O. hadiatyae is among the Malili Lakes ricefish most similar to O. marmoratus . From that species it is clearly distinguished by presence (vs. absence) of the well marked concavity on the snout. Furthermore, the orientation of the mouth differs (slightly upwards vs. almost horizontal; see Fig. 5 ), as well as the greater preanal length [>63.2% SL vs. 54.1–60.8% SL ( Kottelat 1990a) / 56.1–62.7% SL, present study] and prepelvic length (47.8–67.6% SL vs. 42.2–47.6% SL ( Kottelat 1990a) / 44.3–48.9% SL, present study). In addition, O. hadiatyae does not show distinct margins and purple (life) or blackish (preserved) longitudinal stripes in male caudal fin as in O. marmoratus ; females do not show lateral blotches, and have a darker brown lateral body than males (vs. lateral body lighter brown in females than in males).

Description. – See Fig. 3 for general appearance in lateral view, Fig. 4 for radiographs of the male holotype and a female paratype, and Table 1 for morphometric data. Body laterally compressed, elongated. Snout slightly elongated, mouth terminal, upwardly directed, with a pharyngeal knob at ventral profile of head. No external teeth. Dorsal head profile concave on snout. Dorsal body profile almost straight from a small hump at nape to dorsal fin. Ventral body profile convex from snout to anal fin origin in females, only slightly convex to almost straight from posterior ventral head to anal fin in males. Caudal peduncle 1.1–1.6 times longer than deep; caudal peduncle length 9.5–13.4% SL, caudal peduncle depth 7.5–10.5% SL. Genital papilla small and tubular in males, large, bilobed and rounded in females. Eye relatively large, diameter 8.8–14% SL. Orbits meet or slightly project beyond dorsal surface of head.

Scales: 27–31 cycloid scales along lateral midline, ½ 10–14 transversal rows at dorsal fin origin. Dorsal fin origin above 10–12th anal ray, with 8–10 rays; pointed but small, not reaching caudal base in females, fin filamentous, elongated with tip reaching or extending past caudal base in adult males; rays 2–5 are the longest. Anal fin with 19–22 rays, straight to slightly concave in females, convex with slightly elongated, filamentous rays in males. Pelvic fin with 5–6 rays (5 in just one specimen), small, the last ray connected to the body by a membrane along its proximal half to its whole length. Pectoral fin with 10–11 rays, falcate, reaching slightly beyond pelvic origin. Caudal fin truncate to slightly emarginate, with two simple rays at upper and lower margin respectively and nine (3/2/4+5/2/3) branched rays. Vertebrae number 28–30.

Live colouration. – Body yellowish brown to grey. Belly and throat white to light yellowish. Lateral body of males covered with pattern of small irregular blackish blotches or spots scattered around a faint, narrow brownish axial stripe. Dorsal surface of head blackish to brown, extending posteriorly as narrow black dorsal stripe to dorsal and caudal fin. Dorsal surface of snout dark brown, side of snout brownish grey. From eye to anus, ventral body and head white to light yellowish. Opercle with silver bluish sheen. Iris iridescent blue. Fins yellowish hyaline, with brownish rays. In males, dorsal and anal fin blackish brown; male anal fin with a narrow blackish margin. In some adult males, small blackish spots are present on anal-fin.

Preserved colouration. – See Fig. 3 for preserved pigmentation. Body yellowish brown to grey. Faint black lateral stripe present on lateral midline, extending from uppermost posterior extremity of opercle to caudal base. In males, the light brown lateral body is covered with a pattern of up to 14 small blackish blotches or spots, distributed mainly along and around lateral midline. In females, the lateral body is dark brown, a faint blackish axial stripe is present but blackish lateral spots or blotches are absent. Belly blackish grey; ventral body above anal fin and at caudal peduncle light yellowish brown. Dorsal surface of head blackish, extending posteriorly as narrow black dorsal stripe to dorsal- and caudal fin. Throat light yellowish brown. Fins dusky grey hyaline to light brown, with narrow blackish anal fin margin in males. A single blackish blotch or short bar is present on anterior upper opercle in males and females.

Sexual dimorphism. – Females grow larger than males (maximum SL recorded: 40.3 mm in males, 46.1 mm in females) and differ in colouration as described above. Males have elongated dorsal and anal fins which are dark with blackish margins in life.

Distribution and habitat. – Oryzias hadiatyae is known exclusively from Lake Masapi, westwards of Lake Towuti in Central Sulawesi, Indonesia. This blackwater lake is almost circular and only a few meters deep, surrounded by rain forest. Oryzias hadiatyae has been collected from the southern shore to the lake’s outlet area in its southwestern corner, including areas of gentle current. This species appeared to be associated with roots of the Pandanus sp. vegetation characteristic of the lake’s shallow shoreline habitats. As Pongkeru River, the lake’s only tributary, has not yet been sampled, it remains unknown if the distribution of O. hadiatyae extends downstream. The only other native fish known from the lake is a species of Anguilla, which is exploited occasionally and gave the lake its local name, Masapi, Bahasa for Eel.

Like in the other lakes of the Malili lakes system, Lake Masapi has not remained unaffected by increasing population density (see Herder et al. 2006a for comments). While its distant location prevented, at least to date of the present collection, permanent settlements and water management activities, massive logging activities in areas close by are expected to affect the lake in the near future. Moreover, predatory snakeheads ( Channa striata ) were introduced, which use the same shallow shoreline habitats as O. hadiatyae and appear likely also to affect the endemic ricefish population.

Etymology. – The specific name, hadiatyae , honors Renny Kurnia Hadiaty who contributed significantly to the exploration of fish diversity in the Malili Lakes area. Renny also discovered this endemic ricefish in remote Lake Masapi.

Comparative material. – Oryzias matanensis Indonesia, Sulawesi: South Sulawesi Province, Larona drainage, Lake Matano : southwestern shore at 02°30.149'S 121°19.416'E; F. Herder, R. K. Hadiaty & J. Schwarzer coll., Oct.2002: MZB 18509, 1 ex. (43.4 mm SL); ZFMK 41551–41552 , 2 ex. (39.5–40.2 mm SL); ZSM 39767–39768 , 2 ex. (both 39.9 mm SL); southwestern shore at 02°28.458'S 121°15.570'E; F. Herder & R. K. Hadiaty coll., 8 Nov.2002: MZB 18511, 1 ex. (41.5 mm SL); northern shore at 02°27.342'S 121°21.624'E; F. Herder, R. K. Hadiaty, J. Pfaender & J. Schwarzer coll., 5 Nov.2004: 2 ex., MZB 18507 & MZB 18510 (36.4–37 mm SL); ZFMK 41553–41554 , 2 ex. (37.8–37.87 mm SL); ZSM 39769, 1 ex. (36.1 mm SL); northwestern shore at 02°25.649'S 121°17.144'E; F. Herder, R. K. Hadiaty & J. Schwarzer coll., Oct.2002: 1 ex., MZB 18508 (45.6 mm SL) .

Oryzias marmoratus , Indonesia, Sulawesi: South Sulawesi Province; Larona drainage, Lake Lontoa: southwestern shore at 02°40.474'S 121°43.068'E; F. Herder, R. K. Hadiaty, J. Pfaender & J. Schwarzer coll., 3 May 2004: MZB 18512– 18513 , 2 ex. (29.2– 23.8 mm SL); ZFMK 41560–41564 , 5 ex. (26–35.4 mm SL); Lake Towuti : northwestern shore at 02°41.335'S, 121°25.897'E; F. Herder & A. Nolte coll., 30 Nov.2002: MZB 18514–18515 , 2 ex. (34.2–40.9 mm SL) .

Oryzias cf. marmoratus , Indonesia, Sulawesi: South Sulawesi Province, Larona drainage, Lake Towuti : northwestern shore at 02°41.335'S 121°25.897'E; F. Herder & A. Nolte coll., 30 Nov.2002: ZSM 39770–39771 , 2 ex. (36–39.9 mm SL).

Oryzias profundicola , Indonesia, Sulawesi: South Sulawesi Province, Larona drainage, Lake Towuti : northwestern shore at 02°41.335'S 121°25.897'E; F. Herder & A. Nolte coll., 30 Nov.2002: ZFMK 41555–41556 , 2 ex. (39.7–47.5 mm SL) .

Oryzias celebensis , Indonesia, Sulawesi: South Sulawesi Province: Bantimurung Karst of Maros, Patunuang ; J. Harun, 10 Jun.2006: MZB 18518, 15 ex. (32.2–38.7 mm SL); R. K. Hadiaty coll., 20 Jul.2007; ZFMK 41565–41592 , 28 ex. (28.6–38.1 mm SL); S. Rumbia; R. K. Hadiaty coll., 27 Jul.2007 ZFMK 41593–41612 , 20 ex. (22.8–26.6 mm SL) .

Figures

Fig. 3. A: Oryzias hadiatyae, new species, MZB 18491, holotype, male, 34.2 mm SL, male; B: ZFMK 41544, paratype, female,

Fig. 4. Radiograph of Oryzias hadiatyae. A: Oryzias hadiatyae, MZB 18491, holotype, male, 34.2 mm SL, male; B: ZFMK 41544, paratype, female, 43.2 mm SL.

Fig. 5. Diagrammatic representation of the head of (A) Oryzias hadiatyae, new species, paratytype ZFMK 41540, compared to the other lacustrine Oryzias species of the Malili Lakes system: (B) O. marmoratus (ZFMK 41562), (C) O. profundicola (ZFMK 41555), (D) O. matanensis (ZFMK 41551), and (E) stream-dwelling O. celebensis (MZB 18518).