Bull. Natl. Mus. Nat. Sci., Ser. A, 49(4), pp. 191–196, November 22, 2023
DOI: 10.50826/bnmnszool.49.4_191

A New Boxﬁsh of the Genus Kentrocapros Collected from New Zealand(Acanthopterygii, Tetraodontiformes, Aracanidae)
Keiichi Matsuura
Department of Zoology, National Museum of Nature and Science,
4–1–1 Amakubo, Tsukuba, Ibaraki 305–0005, Japan
E-mail: matsuura@kahaku.go.jp(Received 7 July 2023; accepted 20 September 2023)

https://zoobank.org/urn:lsid:zoobank.org:pub:E65D783D-3E0A-49F6-901F-595BE475D025

Abstract A new boxﬁsh, Kentrocapros ﬂavimaculatus, is described on the basis of two specimens collected from New Zealand. The new species is distinguished from all other species of Kentrocapros by the following combination of characters: many yellow spots on the lateral sides of thebody, a distinct spine on the middle of each dorsolateral ridge of the carapace, no spines on the lateral and ventrolateral ridges, and the gill opening located below the posterior half of the eye.
Key words: boxﬁsh, taxonomy, Kentrocapros ﬂavimaculatus, distribution.

Introduction
Boxﬁshes of the genus Kentrocapros are distinguished from other genera of the Aracanidaeby the following combination of characters (Matsuura and Tyler, 1997; Matsuura, 2006, 2015):
the body hexagonal in cross section and the carapace with six longitudinal ridges, three on eachside––dorsolateral, lateral and ventrolateral. Kentrocapros is currently represented by ﬁve species,Kentrocapros aculeatus (Houttuyn, 1782), Kentrocapros eco (Philipps, 1932), K. ﬂavofasciatus(Kamohara, 1938), K. rosapinto (Smith, 1949),
and K. spilonotus (Gilbert, 1905).
Two specimens of Kentrocapros were collected from New Zealand: one from 144–147 m
depth around the Rangitāhua Kermadec Islands
and the other from 145–172 m depth 700 km
north-east of Cape Reinga of North Island. The
two specimens diﬀer from the ﬁve known species by the following combination of characters:
many yellow spots on the lateral sides of the© 2023 National Museum of Nature and Sciencebody, a distinct spine on the middle of the dorsolateral ridge of the carapace, no spines on the lateral and ventrolateral ridges of the carapace, andthe gill opening located below the posterior halfof the eye. They are herein described as a new
species under the name of Kentrocapros ﬂavimaculatus.
Methods
Measurements were made in accordance withthe manner of Hubbs and Lagler (1958), except
for the following: head length (HL), the distancefrom the tip of the snout to the dorsal end of thegill opening; body depth, the vertical measurement from the ventral edge of the ventrolateralridge to the dorsalmost portion of the carapace
vertically above the pectoral-ﬁn base; bodywidth, the distance between the left and right dorsolateral ridges vertically above the pectoral-ﬁnbase; greatest body width, the distance between
the left and right ventrolateral ridges at the middle of the ridges; gill opening length, the distance

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between the dorsal and ventral extents of the gill
opening; postorbital length, the least distancefrom the dorsal end of the gill opening to theorbit; eye diameter, the greatest width of the orbit(not the eye); interorbital width, the least bony
interorbital width, measured at the anterior edgesof the orbits; caudal peduncle length, the distancefrom the posterior edge of the structural base of
the last anal ray to the middle of the caudal-ﬁnbase; caudal-ﬁn length, the distance from themiddle of the caudal-ﬁn base to the tip of the longest ray; tail length, the distance from the posterior edge of the lateral ridge of the carapace to themiddle of the caudal-ﬁn base; tail depth, the vertical distance between the posterior edges of thestructural bases of the last dorsal and anal rays.
Fin ray counts were taken as the total numberof elements, regardless of whether the rays are
branched or unbranched. Paratype data areshown in parentheses when diﬀerent from thoseof the holotype.
Institutional abbreviations are as follows:
AIM, Auckland Institute and Museum, Auckland; BSKU, Department of Biological Science,
Faculty of Science and Technology, Kochi University, Kochi; NMNZ, Museum of New Zealand, Te Papa Tongarewa, Wellington; andNSMT, National Museum of Nature and Science,Tsukuba.
Kentrocapros ﬂavimaculatus n. sp.
(New English name: Yellow-spotted Boxﬁsh;
Japanese name: Kimadara-itomaki-fugu)(Fig. 1)

urn:lsid:zoobank.org:act:A24E15CE-0C17-4552-9035D0E55EDD6B2EKentrocapros eco: Matsuura, 1990, p. 332.
Material examined. Holotype, AIM MA180380,
62.7 mm SL, 30°14′38.4″S, 178°20′3″W, Macauley Island, Rangitāhua Kermadec Islands, 144–147 m depth, 31 Oct. 2016; paratype NSMT-P43344, 114 mm SL, 32°43′S, 167°30′E, Tasman
Sea, 700 km north-east of Cape Reinga of North
Island, New Zealand, 145–172 m depth, 21 Dec.

1983.
Diagnosis. Many yellow spots on the lateralsides of the body, a distinct spine on the middleof each dorsolateral ridge of the carapace, nospines on the lateral and ventrolateral ridges of
the carapace, and the gill opening located below
the posterior half of the eye.
Description. Dorsal-ﬁn rays 10, anal-ﬁn rays
9, pectoral-ﬁn rays 12. Body covered with rigid
carapace except for caudal peduncle, pectoral-,dorsal-, and anal-ﬁn bases, and around anus. Carapace with six ridges, three on each side: dorsolateral, lateral, and ventrolateral ridges; dorsolateralridge starts dorsal to eye and extends posteriorly
to below dorsal-ﬁn origin; lateral ridge originates
behind pectoral-ﬁn base and runs posteriorly toend of carapace; ventrolateral ridge begins below
pectoral-ﬁn base and runs posteriorly to end ofcarapace; middle of dorsolateral ridge with pair ofcompressed spines; posterior half of ventrolateralridge with series of tiny processes.
Most plates on dorsal and lateral sides of carapace hexagonal and sutured ﬁrmly to one
another; each plate with central bony tubercle
from which six (typically) low crests radiate out
to edges of plates. Plates on snout and ventral
surface of carapace variously shaped and articulating with one another. Most parts of caudal
peduncle naked but anterior region covered byseveral small isolated plates.
Dorsal surface of carapace ﬂat; interorbital
space concave; dorsal proﬁle of snout slightly
concave. Ventral side of carapace slightly convex.
Mouth small, terminal; lips ﬂeshy and plicate.
Eight incisiform teeth in single row on each jaw.
Two nostrils close together, just anterior to eye.
Eye large, situated posterodorsally on head. Gill
opening small, slit-like, slightly oblique, ventral
to posterior half of eye. Dorsal and anal ﬁns positioned opposite each other, slightly rounded. Pectoral ﬁn slightly rounded; upper two rays
unbranched; uppermost very short and lowermost unbranched. Caudal ﬁn slightly rounded;dorsalmost and ventralmost rays unbranched.
Proportional measurements. HL 31.1% (26.5%)
SL, snout length 25.0% (23.5%) SL, eye diameter

New boxﬁsh from New Zealand193

Fig. 1. Holotype (A–C) and paratype (D) of Kentrocapros ﬂavimaculatus n. sp. Lateral (A), dorsal (B), and ventral (C) views of holotype (AIM MA180380, 62.7 mm SL), and lateral view of paratype (NSMT-P 43344,114 mm SL). Photographs of A–C, courtesy of AIM.

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16.6% (13.7%) SL, interorbital width 15.0%(12.8%) SL, postorbital length 10.0% (9.0%) SL,gill opening length 8.6% (6.7%) SL, snout to dorsal ﬁn 73.2% (69.6%) SL, snout to anal ﬁn 68.9%(69.7%) SL, body depth 44.0% (39.6%) SL, bodywidth 31.6% (25.0%) SL, greatest body width
37.2% (29.4%), dorsal-ﬁn height 20.6% (17.0%)
SL, anal-ﬁn height 16.9% (18.5%) SL, length of
dorsal-ﬁn base 10.7% (9.5%) SL, length of analﬁn base 8.3% (7.7%) SL, pectoral-ﬁn length
24.7% (19.6%) SL, caudal-ﬁn length 27.9%(24.5%) SL, caudal peduncle depth 7.2% (7.0%)
SL, caudal peduncle length 24.9% (25.3%), taildepth 22.3% (24.0%) SL, tail length 22.3%(25.0%) SL.
Color of fresh specimens. Lateral and dorsal
sides of carapace dark gray; ventral side of carapace white; many yellow spots on lateral sides ofcarapace; many small dark brown spots on dorsal
and dorsolateral sides of carapace; lateral anddorsal sides of caudal peduncle dark gray withseveral yellow spots, ventral side of caudal
peduncle white; ﬁn rays light brownish gray withyellow tinge; and lips red.
Color of preserved specimens. Lateral anddorsal sides of carapace dark gray; many darkbrown spots on dorsal surface of carapace andmany light gray spots on lateral sides of body;
ventral surface of carapace white; lateral anddorsal sides of caudal peduncle dark brown withseveral light gray spots, ventral side of caudal
peduncle white; ﬁn rays dark yellow.
Etymology. The speciﬁc name, ﬂavimaculatus, derived from Latin “ﬂavi” (yellow) and“macula” (spot), refers to the many yellow spots
on the body of the new species.
Remarks. Kentrocapros ﬂaviamculatus issimilar to K. aculeatus and K. spilonotus in having a sharp spine on the middle of the dorsolateral ridge, which is absent in K. eco, K. ﬂavofasciatus, and K. rosapinto, and is distinguishable
from K. aculeatus and K. spilonotus in lacking
spines on the ventrolateral ridges.
Although Philipps (1927) described Ostracion
hexagonus, based on a single specimen washed up
on a beach in the Bay of Islands, New Zealand, helater gave the replacement name, O. eco, to thespecies because O. hexagonus was preoccupied.
Matsuura (1990) provided brief accounts and acolor photograph of a species of Kentrocapros
collected from the northern Tasman Sea under thename of K. eco. However, a subsequent examination of the holotype of K. eco revealed the Tasman
Sea specimen diﬀers from K. eco in having a spineon the middle of dorsolateral ridge, implying it
could be an undescribed species (Matsuura, 2015).
Although Stewart (2015) suggested K. eco may bea senior synonym of K. ﬂavofasciatus the holotypeof K. eco is in too poor a condition (Fig. 2) todetermine its taxonomic identity. I conclude thatK. eco must be regarded as a nomen dubium.
Kamohara (1938) described Aracana ﬂavofasciata based on a single specimen collected from thesea oﬀ Kochi, Japan. Because this species diﬀers
from typical Aracana members in having nospines on the carapace, and resembles Kentrocapros in having six ridges on the carapace, Matsubara (1955) transferred the species from Aracana toKentrocapros. The holotype of K. ﬂavofasciatus
and other type specimens of many species
described by Kamohara were deposited at Kochi
University in Kochi City. All these type specimens
and other ﬁsh collections were unfortunately
destroyed by a war-caused ﬁre in 1945 (Kamohara, 1961). After World War II, Kamohara begancollecting ﬁsh specimens in the sea around Shikoku Island, and was fortunate in obtaining specimens of the species he described before the war.
He published a paper to designate neotypes for themany species he described (Kamohara, 1961), but
his designations do not satisfy article 75 of theICZN, because his paper was not published as arevisory work. Considering the taxonomic problems existing with species of Kentrocapros, I here
designate BSKU 3692 as a neotype of K. ﬂavofasciatus to clarify its taxonomic identity.
Gosline and Brock (1960) regarded Aracana
spilonota Gilbert, 1905 (＝Kentrocapros spilonotus) as a synonym of Ostracion aculeatus Houttuyn, 1782 (＝K. aculeatus). Mundy (2005) followed Gosline and Brock (1960) placing K.
spilonotus in synonymy with K. aculeatus. The

New boxﬁsh from New Zealand

195Fig. 2. Kentrocapros eco, holotype, NMNZ P.000903, 116 mm SL, north of Pahia Bay, Bay of Islands, New Zealand. Photograph, courtesy of NMNZ.

decision is incorrect as K. spilonotus is clearly
distinguishable from K. aculeatus in having thegreatest body width much greater than the body
depth, while the greatest body width is much lessthan the body depth in K. aculeatus, and K. spilonotus lacks the black spots on the sides of thebody that are present on the sides of the body ofK. aculeatus.

Key to the Species of Kentrocapros(K. eco is excluded as a nomen dubium)
1a. Distinct spine on the middle of dorsolateral ridge ............................................................................2
1b. No spine on the dorsolateral ridge ....................................................................................................32a. Several spines on lateral and ventrolateral ridges .............................................................................42b. No spines on lateral and ventrolateral ridges ................................ K. ﬂavimaculatus (New Zealand)
3a. Gill opening slightly oblique, located below posterior half of eye; anterior end of gill opening
reaching below center of eye............................K. ﬂavofasiatus (Japan, South China Sea, eastern Australia, and New Caledonia)
3b. Gill opening almost vertical or very slightly oblique, located below posterior edge of eye; anterior
end of gill opening not reaching below center of eye........................K. rosapinto (western Indian Ocean and Vema Seamount in eastern South Atlantic)
4a. Greatest body width less than body depth; many black spots on lateral side of body........................................... K. aculeatus (East China Sea, Sea of Japan, and Paciﬁc coast of Japan)
4b. Greatest body width greater than body depth; no black spots on lateral side of body.......................................................................... K. spilonotus (Hawaiian Islands and Laysan Island)

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Acknowledgments
I am grateful to Tom Trnski (AIM) for making
the holotype of Kentrocapros ﬂavimaculatus andits photographs available for my study. I thankCarl D. Struthers (NMNZ) for providing me thephotograph of the holotype of K. eco. My thanks
also go to Martin F. Gomon of the Museum Victoria for his helpful comments to the manuscript.
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