A new endemic species of pelvic-brooding ricefish (Beloniformes: Adrianichthyidae: Oryzias) from Lake Kalimpa'a, Sulawesi, Indonesia

Abstract

Oryzias kalimpaaensis sp. nov. is a new species of the genus Oryzias Jordan & Snyder, 1906, endemic to Lake Kalimpa’a in Lore Lindu National Park, Central Sulawesi, Indonesia. The species is a pelvic-brooder, a non-monophyletic group of ricefishes in which females carry an egg cluster until hatching. Pelvic-brooding is known from only a few taxa, and the new species reported here is only the fifth pelvic-brooding species known so far. Oryzias kalimpaaensis sp. nov. differs from all others Oryzias species by the following combination of characters: 61–67 scales in lateral line, 11–13 dorsal-fin rays, 11–13 pectoral-fin rays, body depth 16.0–22.2% SL, and length of head 30.1–33.7% SL. It is distinguished from all species of the genus Adrianichthys Weber 1913, by its small size (max. 52.8 mm SL). A molecular phylogeny based on mitochondrial ND2 sequences supports the distinctiveness of O. kalimpaaensis sp. nov. Oryzias kalimpaaensis sp. nov. is closely related to pelvic-brooding O. eversi Herder, Hadiaty & Nolte 2012 endemic to Tilanga Pond in Tana Toraja, and to the two species of Lake Lindu in Central Sulawesi, O. sarasinorum (Popta 1905) and O. bonneorum Parenti 2008. As Lake Kalimpa’a is a popular destination for nature tourism, anthropogenic pressure is high. The presence of invasive fish species in the lake and parasites on collected specimens support thiss assumption.

Full text

Received: 18.03.2022 Corresponding editor: R. Peters
Accepted: 24.06.2022 Published: 30.06.2022
Bonn zoological Bulletin 71 (1): 77–85 ISSN 2190–7307
2022 Gani A. et al. http://www.zoologicalbulletin.de
https://doi.org/10.20363/BZB-2022.71.1.077
INTRODUCTION
Sulawesi is one of the ve largest islands in Indonesia,
and harbors a rich fauna of freshwater shes, including
endemic lake- and stream-dwelling species (Kottelat
1990a, 1990b; Miesen et al. 2016; Hadiaty 2018). The
island is a hotspot of ricesh diversity (Adrianichthyidae;
reviewed by Hilgers & Schwarzer 2019), and almost all
ricesh species known from it are endemic. Distribution
areas of most species are small, typically restricted to sin-
gle lakes like those of the Malili Lakes system, Lake Lin-
du, or Lake Poso; some riceshes are even restricted to
tiny pools or ponds, or stretches of rivers (Parenti 2008;
Herder & Chapuis 2010; Parenti & Hadiaty 2010; Herder
et al. 2012; Parenti et al. 2013; Mokodongan et al. 2014).
The genus Oryzias Jordan & Snyder, 1906 is the most
diverse and consists of thirty-two species; four species
restricted to Lake Poso make up the endemic genus Adri-
anichthys Weber, 1913.
Abstract. Oryzias kalimpaaensis sp. nov. is a new species of the genus Oryzias Jordan & Snyder, 1906, endemic to Lake
Kalimpa’a in Lore Lindu National Park, Central Sulawesi, Indonesia. The species is a pelvic-brooder, a non-monophyletic
group of riceshes in which females carry an egg cluster until hatching. Pelvic-brooding is known from only a few taxa,
and the new species reported here is only the fth pelvic-brooding species known so far. Oryzias kalimpaaensis sp. nov.
differs from all others Oryzias species by the following combination of characters: 61–67 scales in lateral line, 11–13
dorsal-n rays, 11–13 pectoral-n rays, body depth 16.0–22.2% SL, and length of head 30.1–33.7% SL. It is distinguished
from all species of the genus Adrianichthys Weber 1913, by its small size (max. 52.8 mm SL). A molecular phylogeny
based on mitochondrial ND2 sequences supports the distinctiveness of O. kalimpaaensis sp. nov. Oryzias kalimpaaensis
sp. nov. is closely related to pelvic-brooding O. eversi Herder, Hadiaty & Nolte 2012 endemic to Tilanga Pond in Tana
Toraja, and to the two species of Lake Lindu in Central Sulawesi, O. sarasinorum (Popta 1905) and O. bonneorum Parenti
2008. As Lake Kalimpa’a is a popular destination for nature tourism, anthropogenic pressure is high. The presence of
invasive sh species in the lake and parasites on collected specimens support thiss assumption.
Key words. Endemic, Oryzias, freshwater sh, Kalimpa’a, pelvic-brooder.
Research article
urn:lsid:zoobank.org:pub:2EB89B65-13FE-4194-AA5F-06C172C78554
A new endemic species of pelvic-brooding ricesh
(Beloniformes: Adrianichthyidae: Oryzias)
from Lake Kalimpa’a, Sulawesi, Indonesia
Abdul Gani1, Novian Suhendra2, Fabian Herder3, Julia Schwarzer4, Jan Möhring5, Javier Montenegro6,
Muh. Herjayanto7 & Daniel F. Mokodongan8,*
1Faculty of Fisheries, Muhammadiyah Luwuk University, Banggai Regency, Central Sulawesi, Indonesia
2Fish Quarantine Station, Quality Control and Safety of Fishery Products, Palu, Central Sulawesi, Indonesia
3, 5 Leibniz Institute for the Analysis of Biodiversity Change (LIB) – Museum Koenig, Section Ichthyology Adenauerallee 127,
D-53113 Bonn, Germany
4
Leibniz Institute for the Analysis of Biodiversity Change (LIB) – Museum Koenig, Section Evolutionary Genomics,
Adenauerallee 127, D-53113 Bonn, Germany
6
Japan Agency for Marine-Earth Science and Technology, Kanagawa, Yokozuka, Japan
7
Department of Fisheries Science, Faculty of Agriculture, University of Sultan Ageng Tirtayasa, Serang,
Banten 42124, Indonesia
8
Museum Zoologicum Bogoriense, Research Center for Biosystematics and Evolution,
the National Research and Innovation Agency, Cibinong, Indonesia
*Corresponding author: Email: daniel_mokodongan@yahoo.com
1
urn:lsid:zoobank.org:author:EE6892C6-F3FB-4794-BE18-323078AEAE58
2 urn:lsid:zoobank.org:author:8AA46AC3-1D92-4264-8991-388F40217B6C
3 urn:lsid:zoobank.org:author:A9906501-CD1C-4030-AA13-CF80F98BA106
4 urn:lsid:zoobank.org:author:70E7E37B-39A0-449E-9CF9-BBB51E83C577
5 urn:lsid:zoobank.org:author:8AB210AF-11F4-452C-9470-159BD187160D
6 urn:lsid:zoobank.org:author:01CBD81E-C4DD-45D5-A19D-A3878DD0C9BC
7 urn:lsid:zoobank.org:author:41A2A48D-1F92-4DB8-9ED8-D7B397691F5A
8 urn:lsid:zoobank.org:author:D5B8C0EF-47B1-4CE1-9850-36A6FD05E188

Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
Abdul Gani et al.78
Reproduction of Sulawesi riceshes can be assigned
to two general strategies, transfer-brooders, i.e., spe-
cies that deposit fertilized eggs on a substrate, as it is
the case with most adrianichthyids, and pelvic-brooders
(Parenti 2008; Spanke et al. 2021). In pelvic-brooding
riceshes, females carry the fertilized eggs until the fry
hatches, protected in a ventral concavity, and covered by
elongated pelvic ns (Parenti 2008; Parenti & Hadiaty
2010; Parenti et al. 2013; Mokodongan et al. 2014; Man-
dagi et al. 2018; Spanke et al. 2021). Interestingly, pel-
vic-brooding occurs in species of both genera, Oryzias
and Adrianichthys. So far, a total of four pelvic-brood-
ing riceshes has been reported: A. oophorus (Kottelat,
1990), A. poptae Weber & de Beaufort, 1922, O. sara-
sinorum (Popta, 1905) and O. eversi Herder, Hadiaty &
Nolte, 2012 (Kottelat 1990a; Parenti 2008; Herder et al.
2012; Mokodongan & Yamahira 2015).
Here we describe a new species of pelvic-brooding
Oryzias endemic to a small lake in Central Sulawesi,
Lake Kalimpa’a, which is located within Lore Lindu Na-
tional Park, close to Lake Lindu. This discovery brings
the number of recognized ricesh species on Sulawesi to
23, including at least ve pelvic brooders (Parenti 2008;
Herder & Chapuis 2010; Parenti & Hadiaty 2010; Herder
et al. 2012; Parenti et al. 2013; Mokodongan et al. 2014;
Mandagi et al. 2018; Utama et al. 2022).
MATERIAL AND METHODS
Species description and specimens of the new Oryzias
were collected from Lake Kalimpa’a (Fig. 1) in Cen-
tral Sulawesi, at 1°19′36.1″ S, 120°18′26.1″ E, approx-
imately 23 km east of Lake Lindu (Fig. 2). The sh were
caught with a hand net 13 Sep. 2020. Immediately after
capture, specimens of both sexes were photographed in
a small tank to document life coloration. For morpho-
logical investigations, 18 individuals (10 males and 8
females) were anesthetized using ice slurry, preserved
in 5% formalin for morphological analyses and later
transferred to 70% ethanol for storage. Specimens are
deposited in the sh collections of Museum Zoologicum
Bogoriense (MZB), BRIN in Cibinong; Museum Koe-
nig, Bonn (ZFMK); the Zoological Reference Collection
(ZRC) of the Lee Kong Chian Natural History Museum,
National University of Singapore.
Following Parenti (2008) we distinguished the speci-
mens as genus Oryzias by several characters including
maximum size in adult sh 52.8 mm SL. Specimens
were compared to all known Sulawesi Oryzias species,
with emphasis to those from Central Sulawesi and oth-
er pelvic-brooding species (Lake Lindu: O. sarasinorum
and O. bonneorum; Tilanga Pond: O. eversi; Lake Poso:
O. nebulosus Parenti & Soeroto 2004, O. nigrimas
Kottelat 1990, O. orthognathus Kottelat 1990, and Lake
Tiu: O. soeroto Mokodongan, Tanaka & Yamahira 2014).
Assessment of morphological traits follows Herder et al.
(2012). Number of n rays and scales were counted di-
rectly from each individual using a stereo-microscope
(SWIFT- S306S-20-2L).
To investigate phylogenetic relationships, NADH
dehydrogenase subunit 2 (ND2) gene region was se-
quenced using two primers ND2L (5’-GGGCCCCAT-
ACCCCAAACATGTTGG-3’) and ND2H (5’-TTAAT-
TAAAGTGTCTGTTTTGC-3’) following Mokodongan
and Yamahira (2015). DNA was extracted from the right
pectoral n of two different uncatalogued individuals of
O. kalimpaaensis sp. nov. using standard protocol Qia-
gen DNeasy Blood & Tissue Kit. PCR conditions were
as following: 94 °C for 3 min for denaturation, 35 cycles
Fig. 1. Lake Kalimpa’a: type locality of Oryzias kalimpaaensis sp. nov., in Central Sulawesi, Indonesia.

A new endemic species of pelvic-brooding ricesh from Lake Kalimpa’a, Sulawesi, Indonesia
Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
79
of 94 °C for 30 s, 50 °C for 30 s, and 72 °C for 60 s, with
a nal extension of 72 °C for 2 min. Positive amplica-
tion was veried on a 1% agarose electrophoresis gel.
PCR products were then sent to PT. Genetika Science in
Jakarta (http://actagen.com) for sequencing. Sequence
information for the new species were aligned together
with sequences of 21 other species (two Adrianichthys
and 19 Oryzias) obtained from Mokodongan & Yama-
hira (2015); accession numbers LC051687-LC051739.
Alignments were done via ClustalW ver. 1.4 (Thompson
et al. 1994) and manually curated. The nal alignment
consisted of 1046 bp. Sequence data of O. kalimpaaen-
sis sp. nov. and O. bonneorum were deposited in DNA
Data Bank of Japan (DDBJ) with accession number
LC669549-LC669550, and LC685422-LC685423, re-
spectively. Phylogenetic reconstructions using Maximum
Likelihood were performed in raxmlGUI 2.0.6 (Edler
et al. 2021), following the substitution model selected as
best tting (GTR-I-G) by ModelTest-NG (Darriba et al.
2019) and with 1000 bootstrap replicates conducted.
Cololabis saira (Brevoort 1856) (Beloniformes: Scomb-
eresocidae) was used as outgroup with DDBJ accession
number AP002932.
Taxonomy
Oryzias kalimpaaensis sp. nov.
urn:lsid:zoobank.org:act:045555C9-BD02-4A5A-AFC0-1D2958A806EE
Lake Kalimpa’a Ricesh
Figs 3–4
Holotype
MZB. 26462 (Figs 3 (top), 4), ♂, 41.9 mm SL, Indonesia,
Sulawesi Tengah, Regency of Lore Utara, District Poso,
Lake Kalimpa’a, 13 Sep. 2020, Abdul Gani and Novian
Suhendra.
Paratypes
MZB 26463–26466; 26528-26529, 4 ♂♂ (44.1–50.2 mm
SL), 2 ♀♀ (41.1–42.4 mm SL); ZFMK ICH-128486–
128492, 4 ♂♂ (43.7–49.1 mm SL), 3 ♀♀ (41.8–43.6 mm
SL); ZRC 62531, 2 ♂♂ (47.3–47.6 mm SL), 2 ♀♀ (46.9–
52.8 mm SL), collected with the holotype.
Fig. 2. Map of streams and lakes in Lore Lindu national park (Central Sulawesi, Indonesia) including the type locality of Oryzias
kalimpaaensis sp. nov. (map by Moh. Arif Rahman). The location of the lake Kalimpa’a in Sulawesi is marked by a green dot on
the map in the upper right corner.

Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
Abdul Gani et al.80
Diagnosis. Oryzias kalimpaaensis sp. nov. is a pel-
vic-brooding ricesh with pronounced sexual dimor-
phism. Females share with females of other pelvic-brood-
ing riceshes (O. eversi, O. sarasinorum, A. oophorus)
morphological structures that enable the maternal sh to
carry bundles of fertilized eggs. The eggs remain con-
nected to the female by laments, and are carried in a
ventral concavity present in females but not in males.
Oryzias kalimpaaensis sp. nov. differs from all other
Oryzias species from Sulawesi by unique lateral line
scale counts (60–67 in O. kalimpaaensis sp. nov. vs.
70–75 in O. sarasinorum, vs. <58 in all remaining Sula-
wesi Oryzias). It has a deeper body than O. sarasinorum
(16.0–22.2% SL vs. 13–15% SL). Oryzias kalimpaaensis
sp. nov. has more dorsal-n rays (11–13) than O. hadiat-
yae Herder & Chapuis 2010 (8–10), O. celebensis (Weber
1894) (8–10), O. woworae Parenti & Hadiaty 2010 (8),
O. asinua (7–9), O. wolasi Parenti, Hadiaty, Lumban-
tobing & Herder 2013 (7–9) and O. dopingdopingensis
Mandagi, Mokodongan, Tanaka & Yamahira 2018 (8–9),
and more pectoral-n rays (11–13) than O. eversi (10).
In contrast to riceshes of the O. woworae species
group (SE Sulawesi: O. woworae, O. asinua, O. wola-
si) O. kalimpaaensis sp. nov. does not exhibit red color
in ns or bluish body coloration. Black blotches or lines
on the lateral side of body are characteristic for O. cel-
ebensis (Parenti, 2008), but absent in O. kalimpaaensis
sp. nov.. Oryzias kalimpaaensis sp. nov. has a relative-
ly long head (30.1–33.7% SL) compared to O. sara-
sinorum (29% SL), O. eversi (28.4–30.7% SL), O. soer-
otoi (21.4–25.4% SL), O. orthognathus (22–26.1% SL),
O. nigrimas (21.5–25% SL), O. nebulosus (23–26% SL),
O. marmoratus (Aurich 1935) (24.0–27.2% SL),
O. matanensis (Aurich 1935) (25–29% SL), O. pro-
fundicola Kottelat 1990 (22–25.4% SL), O. celebensis
(24–26% SL), O. woworae (24–29% SL), O. asinua (25–
30% SL), O. wolasi (25–30% SL) and O. dopingdopin-
gensis (25.8–29.1% SL). Its anal-n base is short (19.2–
24.0% SL) compared to O. soerotoi (24.1–30.5% SL),
O. orthognathus (26.2–31.6% SL), O. nigrimas (24.5–
29.9% SL), O. nebulosus (25–29% SL), O. marmoratus
(31.4–36.9% SL), O. matanensis (30.5–35.0% SL) and
O. profundicola (37.4–41.4% SL). The snout concavity
characterizing O. hadiatyae and O. orthognathus is ab-
sent in O. kalimpaaensis sp. nov..
Oryzias kalimpaaensis sp. nov. is distinguished from
Adrianichthys spp. by its smaller adult body size (max-
imum size 52.8 mm SL, vs. 200 mm) (Parenti, 2008),
Fig. 3. Living specimens of Oryzias kalimpaaensis sp. nov., ♂ (top) and ♀ (bottom) from Lake Kalimpa’a, Central Sulawesi,
Indonesia.

A new endemic species of pelvic-brooding ricesh from Lake Kalimpa’a, Sulawesi, Indonesia
Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
81
and differs from all Adrianichthys except A. oophorus by
having less anal-n rays (20–22 vs. >23). From A. oo-
phorus, it is distinguished by having more dorsal-n rays
(11–13 vs. 10) and longer head (30.1–33.7% SL vs. 25–
27% SL (Parenti, 2008).
Etymology. The species epithet, ‘kalimpaaensis’, de-
notes the occurrence of this species in Lake Kalimpa’a,
Central Sulawesi, the type locality.
Description. See Fig. 3 and Fig. 4 for general appear-
ance in lateral view and table 1 for morphometric data.
Female with pronounced abdominal concavity between
pelvic n and anal n covered by adpressed pelvic ns
(11.7–19.0% SL). Body compressed laterally, body depth
16.0–22.2% SL. Caudal n truncate; principal caudal-n
rays i,4/5,i; procurrent caudal-n rays 6/6–6/8. Mouth
supra-terminal, lower and upper jaw equal or lower jaw
slightly longer than upper jaw. Length of caudal pedun-
cle 10.3–14.4% SL, depth of caudal peduncle 10.0–
12.1% SL. 11–13 dorsal-n rays; 20–22 anal-n rays;
5–6 pelvic-n rays; 11–13 pectoral-n rays.
Head length 30.1–33.7% SL and eye diameter 25.0–
29.6% HL. Dorsal head prole appears slightly concave
just above the orbit to the nape. Dorsal body prole rel-
atively straight without noticeable arch from nape to
dorsal-n origin. Ventral body prole relatively straight,
with slight arching from head to anal. Genital papilla sin-
gle lobed in both sexes.
Live coloration. Body yellowish-brown with a
brown-greenish lateral line, more pronounced in females
than in males. Belly and throat light yellowish to white.
7–10 faint blackish bars on lateral side of body. Dorsal
surface of head blackish, extending posteriorly as narrow
black dorsal stripe to dorsal-n origin. Opercle with sil-
ver greenish sheen. Membranes of paired and unpaired
ns hyaline, rays light cream colored. Base of dorsal n
yellowish. Anal-n base with narrow blackish stripe.
Males with black submargin in dorsal and anal n. Fe-
males with blackish submarginal band in anal n, sub-
marginal marking in dorsal n black, submargin lacking
in females. Caudal-n base yellowish, followed posteri-
orly by a faint blackish bar. Dorsal and ventral caudal-n
margins yellowish to orange, more pronounced in males
than in females. Courtship coloration unknown (Fig. 3).
Color in alcohol. Body of males and females light
yellowish-brown. 7–10 faint and irregular dark brown
to blackish bars on lateral body in both sexes. Males
and females with a faint blackish lateral stripe on later-
al midline, extending from uppermost posterior opercle
to caudal-n base. Belly blackish grey in males, whitish
in females. Throat whitish in males and females. Dorsal
surface of head blackish in males and females, extending
posteriorly as narrow blackish dorsal stripe. Unpaired
ns whitish. Anal-n base with narrow blackish stripe.
Faint blackish submargin in anal n. Blackish submargin
present in dorsal n in males, but not in females. Base of
caudal n yellowish in both sexes (Fig. 4).
Sexual dimorphism. Females have a slightly wider
body compared to males (body width: 12.3–14.1% SL in
females vs. 11.7–13.4% SL in males). The single-lobed
genital papilla of males is tubular and slender compared
Fig. 4. Preserved specimens of Oryzias kalimpaaensis sp. nov., holotype (MZB 26462), ♂, 41.9 mm SL (top); paratype (MZB 26466),
♀, 42.4 mm SL (bottom).

Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
Abdul Gani et al.82
to the more rounded female papilla. Adult males have
elongated rays in dorsal and anal n, a typical sexual di-
morphism in riceshes. Length of dorsal n extends be-
yond caudal-n base in adult males (21.2–34.4% SL in
males vs. 14.4–24.9% SL in females). Elongated n-rays
are absent in dorsal and anal ns of females. Females
have longer (13.7–19.0% SL vs. 10.3–12.7% SL) pel-
vic ns compared to males and a pronounced abdominal
concavity between anal n and pelvic n; egg clusters
in the concavity are supported by the pelvic ns (Fig. 3;
Fig. 4). Due to the less pronounced concavity, males
have a larger relative body depth at anal-n origin than
females (19.3–22.2% SL vs. 16.0–20.3% SL). See ‘Live
coloration’ for coloration of male and female specimens.
Reproduction. Oryzias kalimpaaensis sp. nov. is a
‘pelvic-brooder’. Pelvic-brooding is dened by females
carrying a cluster of eggs, connected by attaching la-
ments to their gonoduct, until the fry hatches (Kottelat
1990a). All pelvic-brooding ricesh species described
to date (A. oophorus, A. poptae, O. eversi and O. sara-
sinorum) share certain external female-specic morpho-
logical characteristics like elongated pelvic ns (com-
pared to their respective males and to all transfer-brooding
species) and the presence of a ventral concavity (Herder
et al. 2012; Mokodongan & Yamahira 2015; Spanke et al.
2021). Female specimens of O. kalimpaaensis sp. nov.
carry their eggs on the abdominal concavity covered by
the pelvic ns. As described for the other pelvic-brood-
ing species (Kottelat 1990a; Iwamatsu et al. 2008; Herder
et al. 2012), the eggs do not adhere to each other, and are
suspended by attaching laments to the female’s genital
pore. Approximately 24 eggs were counted from one fe-
male specimen depicted in Fig. 4. The eggs are clearly
developed and partially pigmented with embryos visible.
The size of each fertilized egg is about 2.19±0.10 mm in
diameter.
Distribution and habitat. Oryzias kalimpaaensis
sp. nov. is known only from Lake Kalimpa’a, about
22 km from Lake Lindu, Central Sulawesi, situated at
ca. 1,660 m above sea level. The lake is relatively small,
with the longest distance across the surface being ap-
proximately 300 meters from Southwest to Northeast.
The lake is used by local people as a place for nature
tourism. At time of sampling, most female O. kalim-
paaensis sp. nov. observed were carrying eggs. The
lake habitat is characterized by calm water with sandy
and muddy substrate with vegetation dominated by the
weed Phragmites karka (Retz.) (Cyperales: Poaceae).
The depth of Lake Kalimpa’a is about 11 meters (D. H.
Kristianto & Wantoko Staff of BBTNLL, pers. comm.)
and water temperature was 22 °C with pH 5–6.5 and DO
13.9 Mg/L, measured during daytime. There is a main
inlet of Basakura Stream near the collection site and four
more inlets of small streams around the lake. The Lake
outlet is connected to the Sopu River, a tributary of the
Palu River, which drains into the Makassar Strait. Other
species present in the Lake Kalimpa’a were introduced
african tilapia Oreochromis sp. (Cichliformes: Cichlidae)
and snakeskin gourami Trichopodus pectoralis Regan
1910 (Anabantiformes: Osphronemidae), and native eel
Anguilla sp. (Anguilliformes: Anguillidae).
Phylogenetic relationships. The resulting ML phylog-
eny (Fig. 5) is largely congruent with the consensus tree
of Mokodongan & Yamahira (2015) in all well supported
branches, including the monophyly of all known Oryzias
species from Sulawesi (the “Oryzias celebensis species
group”). The two O. kalimpaaensis sp. nov. individuals
(DDBJ accession numbers: LC669549–LC669550) clus-
ter together and form the sister-group to the two other
pelvic-brooding Oryzias species (O. eversi and O. sar-
asinorum) and O. bonneorum. Oryzias sarasinorum
appears paraphyletic based on our phylogeny, as one
individual clusters with O. bonneorum. Sister-group to
this clade is the river-dwelling transfer-brooding spe-
cies O. dopingdopingensis. Interestingly, O. bonneorum
formed a clade together with the pelvic-brooding Oryzias
species, although it is still unclear whether this species is
a pelvic-brooder or not.
DISCUSSION
Riceshes (Beloniformes: Adrianichthyidae) are a
strikingly diverse group of shes, inhabiting riverine,
lacustrine, and brackish water habitats (Parenti 2008;
Hilgers & Schwarzer 2019). On Sulawesi, they show a
great diversity in coloration, shape, adaptations to diver-
gent habitat conditions and belong to two genera (Adri-
anichthys and Oryzias) with two main reproductive strat-
egies: transfer-brooding and pelvic-brooding. To date
pelvic-brooding is described in four species (A. oopho-
rus, A. poptae, O. sarasinorum and O. eversi), contrasted
by all other ricesh species that are either transfer-brood-
ing or have an unknown reproductive status (i.e., O. bon-
neorum, A. roseni Parenti & Soeroto 2004 and A. kruyti
Weber 1913). More undiscovered diversity appears like-
ly, as riceshes tend to inhabit small isolated habitats (see
Parenti & Hadiaty 2010). Several species of Sulawesi
riceshes are known only from water bodies with small
surface area, i.e., O. soerotoi from Lake Tiu (Mokodon-
gan et al. 2014), O. hadiatyae from Lake Masapi, a small
satellite lake of Lake Towuti (Herder & Chapuis 2010),
O. eversi from Tilanga pond, a tiny karst pool (Herder
et al. 2012), as well as the new species described herein.
Oryzias kalimpaaensis sp. nov. is known only from the
Lake Kalimpa’a, a small upland lake at ~1660 m above
sea level. This is the highest altitude at which ricesh-
es have so far been recorded in Sulawesi. Distance be-
tween Lake Kalimpa’a and the closest habitat of other
pelvic-brooding riceshes – Lake Lindu, the habitat of
O. sarasinorum and O. bonneorum – is only ~22 km
(Fig. 2). However, both are separated by a substantial

A new endemic species of pelvic-brooding ricesh from Lake Kalimpa’a, Sulawesi, Indonesia
Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
83
barrier, the Nokilalaki mountain (2357 m elevation).
Geographic distance to pelvic-brooding Adrianichthys
exceeds 56 km (Lake Poso: A. oophorus, A. poptae) and
to O. eversi (Tilanga Pond) the distance is 194 km.
Based on our phylogenetic analyses, O. kalimpaaen-
sis sp. nov. is closely related to both, the Lake Lindu
riceshes, and O. eversi (Fig. 5). Its placement within
the clade of pelvic- brooding Oryzias appears plausible;
however, the reproductive biology of O. bonneorum re-
mains undocumented (Parenti 2008). The new species is
distinguished from other ricesh species by several mor-
phological characters, supporting that O. kalimpaaensis
sp. nov. is a distinct species.
Although the reproductive ecology of O. kalimpaaesis
sp. nov. has not been studied in detail yet, records of fe-
male O. kalimpaaensis sp. nov. with developing eggs on
their belly (Fig. 3, Fig. 4 bottom) indicate – in line with
the phylogenetic and morphological evidence – that it is
a pelvic-brooding species. As in the other pelvic-brood-
ing species, females show a set of adaptations enabling
brooding, namely elongated pelvic ns, presence of a
ventral concavity and long laments attaching the eggs
to the genital pore.
Lake Kalimpa’a is located in the Lore Lindu National
Park, and is a popular destination for nature tourism. Pro-
tection of the ora and fauna inhabiting the lake should
be implemented, especially with regard to endemic spe-
cies, like O. kalimpaaensis sp. nov.. The most substantial
threats to Sulawesi’s endemic freshwater shes are exotic
sh introduction, eutrophication, overshing, and pollu-
tion (Parenti & Soeroto 2004, Herder et al. 2022). Lake
Kalimpa’a already contains non-native shes such as
African tilapia (Oreochromis sp.) and snakeskin gourami
(Trichopodus pectoralis) (A. Gani & N. Suhendra, pers.
obs.), which might affect together with the direct anthro-
pogenic impact (e.g., through nature tourism) the lake
ora and fauna. We found anchor worms Lernaea sp. in
a female O. kalimpaaensis sp. nov., which indicates that
the population might already suffer stressful conditions;
parasites and disease are one of the causes of the decline
in other endemic lake shes in Sulawesi (Kottelat 1990a;
Herder et al. 2022).
Comparative material examined
Oryzias asinua: MZB 21464, 2, Indonesia, Sulawesi
Tenggara, District Asinua; Oryzias bonneorum: MZB
15499, holotype, Indonesia, Sulawesi Tengah, Lake Lin-
du; Oryzias celebensis: MZB 2688, 4, MZB 5862, 3, In-
donesia, Sulawesi Selatan, Regency of Maros Indonesia;
Oryzias eversi: MZB 20780, holotype, MZB 20781, 1
paratype, Indonesia, Sulawesi Selatan, District Rante-
Fig. 5. Maximum Likelihood (ML) phylogenetic tree with the bootstrap values from 1000 bootstrap replicates. Oryzias kalim-
paaensis sp. nov. is marked in red.

Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
Abdul Gani et al.84
pao; Oryzias hadiatyae: MZB 18491, holotype, MZB
18503, 1 paratype, MZB 18504, 1 paratype, MZB 18505,
1 paratype, MZB 18506, 1 paratype, Indonesia, Sulawesi
Selatan, Lake Masapi; Oryzias marmoratus: MZB 2686,
7, MZB 2690, 1, Indonesia, Sulawesi Selatan, Lake
Wawontoa; MZB 2695, 5, MZB 2697, 5, Indonesia, Su-
lawesi Selatan, Lake Towuti; Oryzias matanensis: MZB
21379, 1, Indonesia, Sulawesi Selatan, Lake Matano;
Oryzias nebulosus: MZB 21381, 2, Indonesia, Sulawesi
Tengah, Lake Poso; Oryzias nigrimas: MZB 5859, holo-
type, MZB 5872, 5 paratypes, Indonesia, Sulawesi Ten-
gah, Lake Poso; Oryzias orthognathus: MZB 5870, ho-
lotype, Indonesia, Sulawesi Tengah, Lake Poso; Oryzias
profundicola: MZB 5868, holotype, MZB 5861, 1 para-
type, MZB 5866, 1 paratype, MZB 5867, 2 paratypes, In-
donesia, Sulawesi Selatan, Lake Towuti; Oryzias wolasi:
MZB 21465, 2, Indonesia, Sulawesi Tenggara, District
males females
holotype paratypes (N = 10) paratypes (N = 7)
MZB26462 min. max. mode min. max. mode
anal-n rays (total) 21 20 22 20 20 22 22
dorsal-n rays (total) 12 11 13 11 11 12 12
pelvic-n rays 5 6 6 6 6 6 6
pectoral-n rays 13 11 13 12 12 12 12
principal caudal-n rays i.4/5.i i.4/5.i i.4/5.i i.4/5.i i.4/5.i i.4/5.i i.4/5.i
procurrent caudal-n rays 6/7 6/6 6/8 6/7 6/6 6/7 6/7
scales in lateral row 66 62 67 66 61 66 64
min. max. mean (SD) min. max. mean (SD)
standard length (mm) 41.9 44.1 50.2 47.5 (±2.2) 41.1 52.8 44.4 (±4.1)
% standard length
total length 122.3 119.3 122.9 120.8 (±1.3) 119.0 121.9 120.1 (±1.0)
head length 33.7 30.1 33.1 31.4 (±1.0) 30.6 33.2 32.0 (±1.0)
head depth 33.7 16.7 32.1 20.7 (±5.9) 18.7 32.9 26.5 (±6.6)
head width 19.5 18.0 21.7 20.0 (±1.1) 18.5 22.4 20.0 (±1.6)
predorsal length 75.4 74.4 78.0 75.4 (±1.1) 73.3 75.9 74.9 (±1.0)
prepelvic length 49.7 49.7 51.8 50.5 (±0.8) 49.2 52.9 51.19 (±1.4)
preanal length 62.6 61.7 64.6 62.7 (±1.0) 61.8 65.7 63.29 (±1.4)
body depth 21.0 19.3 22.2 21.0 (±1.0) 16.0 20.3 18.49 (±1.5)
body width 11.7 12.1 13.4 12.7 (±0.3) 12.3 14.1 13.49 (±0.6)
length of caudal peduncle 10.6 10.3 13.3 11.9 (±1.0) 10.7 14.4 12.09 (±1.3)
depth of caudal peduncle 10.1 10.9 11.5 11.2 (±0.2) 10.0 12.1 11.09 (±0.8)
length of dorsal n 34.4 21.2 29.1 24.5 (±2.4) 14.4 16.1 15.29 (±0.8)
length of dorsal n base 12.8 11.3 13.9 12.7 (±0.7) 10.7 13.1 11.89 (±0.8)
length of anal n base 23.9 19.2 24.0 22.7 (±1.4) 19.4 22.5 21.99 (±1.1)
length of pectoral n 22.7 17.5 21.7 19.2 (±1.5) 17.3 19.8 18.69 (±0.9)
length of pelvic n 10.6 10.3 12.6 11.4 (±0.7) 13.7 18.9 15.89 (±1.8)
% head length
interorbital width 29.4 27.8 36.5 33.0 (±2.6) 30.6 34.2 32.79 (±1.5)
eye diameter 26.9 25.0 28.4 26.7 (±1.1) 26.3 29.6 28.09 (±1.0)
snouth length 34.7 31.5 39.2 35.5 (±2.3) 32.5 39.6 35.29 (±2.3)
Table 1. Meristic and morphometric data of Oryzias kalimpaaensis sp. nov. from Lake Kalimpa’a. Data of the holotype are pre-
sented in a separate column.

A new endemic species of pelvic-brooding ricesh from Lake Kalimpa’a, Sulawesi, Indonesia
Bonn zoological Bulletin 71 (1): 77–85 ©ZFMK
85
Wolasi; Oryzias woworae: MZB 21380, 1, Indonesia,
Sulawesi Tenggara, Muna Island, District Parigi.
Acknowledgements. We would like to thank to Sutrisno K.
Dwaja, the President of Muhammadiyah Luwuk University,
Erwin, W., the Dean of Faculty of Fisheries, Muhammadiyah
Luwuk University, Risno Mina, the Head of LP3M Muham-
madiyah Luwuk University) and Hamzah, M.Si, the Head of
Fish Quarantine Station, Quality Control and Safety of Fishery
Products, Palu, Central Sulawesi with staff Irmawan Syatri-
anto, Nur Halik Lande for supporting this research. Thanks to
Ir. Jusman, the Head of Lore Lindu National Park Hall for the
permit to conduct research in the Lake Kalimpa’a and park staff
Wantoko and Doni Kristianto for supporting us in conducting
eldwork. We thank Fajri Ramadhan (MIPA Faculty, Tadulako
University), Suyanto, Zarlif, Novarman (Mapala Sagartmatha,
Agriculture Faculty, Tadulako University), Rocky Zakaria,
Ramlin, Fadly, Ekspedisi Riset Akuatika (ERA) Indonesia team
for the eld help. Thanks also to Tan Heok Hui and one anon-
ymous reviewer for improving the manuscript. This study was
partially supported by Grant-in-Aid for Early-Career Scientists
number 19K16203 to Javier Montenegro.
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APPENDIX I
(electronic supplement, available at www.zoologicalbulletin.de)
Table S1. All measurements and counts of examined
O. kalimpaaensis; separated in ♂♂ in ♀♀. * holotype.