Adrianichthys roseni, PARENTI & SOEROTO, 2004

Parenti, Lynne R., 2008, A phylogenetic analysis and taxonomic revision of ricefishes, Oryzias and relatives (Beloniformes, Adrianichthyidae), Zoological Journal of the Linnean Society 154 (3), pp. 494-610 : 548-549

ADRIANICHTHYS ROSENI PARENTI & SOEROTO, 2004

ROSEN’ S BUNTINGI

FIGURES 18B , 22 , 24B , 36

Adrianichthys kruyti .- Rosen & Parenti, 1981: 16, fig. 15b [dorsal gill arch osteology].- Parenti, 1989: 80, fig. 1 [photo].

Adrianichthys roseni Parenti & Soeroto, 2004: 10–19 , figs 1, 2a, 5 [type locality: Indonesia: Sulawesi, Lake Poso ].

Differential diagnosis: Adrianichthys roseni is like its sister species, A. kruyti , and differs from congeners, A. oophorus and A. poptae , in having large orbits that project markedly beyond the dorsal profile of the head; paired, rather than single, preethmoid cartilages; and a large dorsal fin (with 13–16 vs. 8–13 dorsal-fin rays). The lower jaw of A. roseni is enclosed in the expanded upper jaw, but the upper jaw is not as large and broadly expanded as in A. kruyti . In addition, A. roseni differs from A. kruyti in having fewer scales in a lateral series (approximately 63–65 vs. 70–75) having more anterior pelvic fins (opposite vertebra 7 as opposed to vertebra 10) and attaining a smaller maximum standard length (90 vs. 109).

Description: Large-bodied, maximum size of specimens examined 90 mm SL. Body slender, laterally compressed; body depth 14–17 [17]. Abdominal concavity between pelvic fins and anal fin. Mouth subterminal, elongate upper and lower jaws, upper jaw slightly longer than, and enclosing, lower jaw. Dorsal and ventral body profile relatively straight from head to dorsal- and anal-fin origins. Head length 31–32 [32]; snout length 14; eye moderate, 7–8, orbits project beyond dorsal surface of head; dorsal surface of head concave, articulation point of palatine and maxilla project slightly beyond dorsal profile. Fleshy, incompletely scaly, basal portion of dorsal and anal fin project slightly beyond primary body profile. Scales small, cycloid and relatively deciduous; 63–65 in a lateral series. Anal-fin rays without contact organs. Large, rounded, urogenital papilla in gravid female holotype. Medialmost pelvic-fin ray not connected to body via a membrane. Caudal fin slightly lunate, dorsal and ventral segmented caudal-fin rays longer than middle rays.

Premaxilla flat and broad with no distinct articular or ascending processes; premaxilla and dentary with pavement dentition comprising four to five irregular rows of small, villiform teeth; no enlarged, caniniform teeth on posterolateral ramus of premaxilla or dentary. Paired preethmoid cartilages; ossified portions of mesethmoid round; anterior border of ethmoid cartilage straight. Palatine and quadrate articulate via elongate flanges that overlap anteriorly. Dorsal ramus of hyomandibula bifid, separate cartilages articulate with sphenotic and pterotic. Lacrimal sensory canal carried in open bony groove. First pleural rib on parapophysis of third vertebra; lateral process of pelvic bone attaches to fifth pleural rib. Caudal skeleton with two epural bones, one relatively large, straight, ventral accessory bone. Fifth ceratobranchial toothplates subtriangular with pavement dentition anteriorly followed posteriorly by eight to nine tooth rows; no small, incomplete posterior row. Basihyal bone elongate and triangular; basihyal cartilage rectangular. Epibranchial elements fully ossified; epibranchial 2 with a broad point of articulation with ceratobranchial cartilage.

Dorsal-fin rays 13–16 [13]. Anal-fin rays 25. Pelvicfin rays 6. Pectoral-fin rays 13–15 [15]. Principal caudal-fin rays i,5/6,i. Procurrent fin-rays, dorsal 6, ventral 7. Vertebrae 36 (14 + 22). Branchiostegal rays 5.

Cytogenetic data: Unknown.

Colour in life: Unknown.

Colour in alcohol: Overall ground colouration pale yellow, belly pale whitish yellow. Faint transverse irregular bar just slightly darker than ground coloration posterior to pectoral fin. Fins hyaline.

Distribution and habitat: Endemic to Lake Poso, Sulawesi Tengah ( Parenti & Soeroto, 2004: fig. 1). No habitat data are available for the single collection of this species. It is presumed to be a pelagic species like its congeners.

Remarks: Measurements were taken on the holotype and paratype. The triple stained nontype is highly distorted and therefore was not measured. Counts were verified on a radiograph of the holotype because the paratype has become disarticulated in glycerin. The three known specimens are all female.

Material examined: Three specimens (69–90 mm SL). Holotype. INDONESIA. Sulawesi Tengah: Lake Poso , N. J. Wilimovsky, 4–5.ix.1978, MZB 6732 (ex. USNM 322424 ), 1 (gravid female, 90 mm).

Paratype. INDONESIA. Sulawesi Tengah: Lake Poso , USNM 322425 , 1 (cleared and counterstained, female, 73 mm), collected with the holotype .

Non-type specimen. INDONESIA. Sulawesi Tengah: Lake Poso , USNM 326628 , 1 (cleared and counterstained for bone, cartilage, and nerves, female, 69 mm), collected with the holotype .

Figures

Figure 18. A. Adrianichthys oophorus, USNM 348386, female, 60 mm SL; B. A. roseni, USNM 322425, female, 73 mm SL. Anterior portion of skull, jaws and jaw suspensorium. The cartilage that may be seen between the two preethmoid cartilages in B is the cartilaginous symphysis of the dentaries. Anterior is up.

Figure 22. Adrianichthys roseni, holotype, MZB 6732, adult female, 90 mm SL. Radiograph.

Figure 24. A, Hemirhamphodon kuekenthali, USNM 330828, adult male, 50 mm SL; B, Adrianichthys roseni, USNM 322425, adult female, 73 mm SL; C, Adrianichthys poptae, USNM 322423, adult female, 168 mm SL; D, Adrianichthys oophorus, USNM 348386, female, 60 mm SL; E, Oryzias bonneorum, ZMA 123.863, adult female, 40 mm SL; F, Oryzias dancena, USNM 342156, adult male, 24.5 mm SL. Diagrammatic representation of the hyoid bar. Arrows indicate posterior extent of the ramus of the ventral hypohyal. Beloniform fishes lack an interhyal. All drawn to same scale.

Figure 36. Adrianichthys roseni Parenti & Soeroto, 2004, Lake Poso, Sulawesi Tengah, Indonesia, MZB 6732, holotype, gravid female, 90 mm SL.