The malacological society of Japan
Ren VENUS (Jap. Joun Malac.) -2e Vol. 48, No. 1 C1989):12-
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More Study on Two Speeies of MexichTomis from Japan
(Nudibranchia: Chromodorididae)
Kikutar6 BABA
(Shigigaoka 35, 1-11-12, Sango-cho, Ikoma-gun, Nara-ken, Japan 636>
Abstract: (1) Gtossodoris multitubeTc2elata Baba, 1953 is moved to the genus
Mexichrovais Bertsch, 1977, and is re-described. (2) Mexichromis .festiva (Angas, 1864>, previously noted to occur in Japan, is more extensively described.
1. Mexichromts muttituberculata (Baba, 1953), comb. n.
(Figs. 1-2)
Synonymy:
Glossodoris multituberculata Baba, 1953: 207-208, fig. 3, fig. 6, C-E (Seto, Kii) ; Rud- man, 1983: 161 and Rudman, 1984: 216 (both eornment on generic alloeation).
Refer alse to:
Mexichromis 7nariei. Rudman, 1983: 151-154, figs, 12F, 21, 22 (Gulf of Kutch, India;
Suakin, Red Sea); Rudman, 1984: fig, 69B, fig. 73, B-C, fig. 74 (anatomy),
MexichToinis. Rudman, 1984: 214-216 (comparative remarks).
Material: Seto, Kii, Nov. 5, 1964, 2 speeimens eell. by the Aquarium, Seto Mar. Biol.
Lab., Kyoto Univ., length about 30 mm eaeh.
Description: The back is closely covered with tubercles of various sizes. The
smallest tubercles are simply conical. The largest tubere]es when fully extended
are in the form of highly raised cones which may beeome rounded at their tops
when contraeted. The branchial plumes, 10-12 in number, are arranged in a
eircle around the anus, Ventrally there are two large mantle glands on each
side of the posterior margin of the mantle.
The ground color of the back is chrome yellow in the central part and pa]er )red- yellow towards the margins. The largest tubercles are eaeh marked with a purple top and a subapical band of opaque white. The lower half of each tubercle
is yellow. The smallest tubercles are overall yellow. On the mantle edge there
is a broad band of opaque white which is regularly interrtipted by red-purple
tubercles. Or, it may be said that the marginal opaque white patches are
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Baba : Two Species of Mexichromis 13
A
y
レ ン ゲ ミ ウ シ Kii Fig.1. Mexichromis mzaltitptberculata ウ (Seto, 紀伊瀬戸 産) A .Entire animal , length 30 mm 全 形背 面 ,体 長 30 mm ; B . Dorsal tubercles when fully extended 背面 突 起 の 伸長 時 ; C . Dorsal tubercles when contracted 背面 突 起 の 収 縮 時 ; D . A single 一 dorsal tubercle seen from the top 背 面 突起 個 を頂端 よ り見 た と こ ろ ; E .Mantle and foot from below 外套 膜 及 び 足 部腹 面 よ り ,
alterna 七ing with the red −purple tubercles regularly . The rhinophore is opaque − white turning to red purple towards the club (or at least towards the tip of the club ). The branchial plumes are yellowish white with the rachis of each − gill red purple . The sides of l)ody and the foo七 including the sole are paler yellow than the dorsum , There is a submarginal band of red −purple on the
length of the foot.
The pharynx is short but the oral tube is much elongated . The labial disc
is cut middorsally . The rodlets of the disc are deeply cleft at their 七ips. The
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14 VENUS; Vol. 48, No. 1 (1989)
', d ' . ii
, Iao li...'/. -O.5 mm .e... rOC{iS>gll) i
d , 4i,il'
s E E E rx . cv O n - - o o 1 t ."N.----SB
20 × 38
- 39
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Fig. 2. n4exichromis mzaltituberculata tr y tr' ij l rk v' (Seto, Kii IEfi,imP.nt:) A. Pharyngeal part from right side PpmutthlyLfptlj: O ; B. Radula deX;C. T.o right half rows ef radula tw'SOa=\deiU.
radulaT formula is 75 × 35-40.0.35-40. The rachidian plate is rudimentary or
missing, The morphology of the Iateral teeth is somewhat as in Mexichromis
mariei・ (Crosse, 1872) from Australia, see Rudman, 1983: 154, fig. 22. The
first lateral toeth has 2-3 denticles on the inside and up to 6 denticles on the
outside of the main eusp which is net mueh produced. The succeeding lateral
teeth have each 6 to 7 denticles on the outside. In each lateral tooth the upper-
most of the outer denticles is next in size to the main cusp and forms a secondary
cusp. Therefore all the lateral teeth appear rather to be bicuspidate at their
tips. The outermost lateral teeth are deereased in size. The genitalia could
not be studied.
Reonarks: Glossodori.s multitubercutata Baba, 1953 is closely eornparable with
Mexichromis mariei (Crosse, 1872) in the raised dorsal tubercles, in having
a few mantle glands and in the composition of the radular teeth. Henee G.
muZtituberculata is assigned to the same genus Mexichromis and called M.
muetitubercutata. This specles ls also similar to M. mariei in several points of
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Baba: Two Species of Mexichromis 15
r
r
mg
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J,t Fig. 3. Mexichromis festiva cr V d p :> .EV v" (Awashima,
Suruga Bay ・waifiIvaivekdi) A. Entire animal, length 25mm SfVUwh, tsft 25mm; B, The same animal from below raMgim.
the coloration of body (purple-topped dorsal tubercles, purple rhinophores, purple gills and a purple marginal band to foot). However, the two species are dis-
similar in details of body colors as follows:
I. MexichTomis mttltituberculcttq: the mantle is ehrome yellow and the opaque white border is regularly interTupted by red-purple tubercles. II. MexichTomis mariei: the rnantle is white and the orange border is inter-
rupted to form a row of orange marks.
The highly raised and readily contractile dorsal tubercles are most characteristic
for the species M'. mu・ltituberculata.
2. Mexichromts festiva (Angas, 1864)
(Figs. 3-5)
Main synonymy:
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No 1 1989 16 VENUS : Vol.48 , , ( )
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ク リ ヤ イ 卩 ウ ミ ウ シ Fig.4. Mexichromis festiva Awashima , Suruga Bay 駿 河 湾 淡 島 産 ) A ,Pharynx from right side 卩囚頭 右 側 よ り ; B . A right half row 一 of radula 歯舌 の 右 半 歯列 ; C. Liver mass from above 肝 臓 部 一 背 面 よ り ; D .Part of genital system from above 生 殖 器 系 部背 面 よ り.
召 Angas : − 4 丘 12 Goniodoris ノ s 亡吻 α , 1864 53 54 , pL , g . (Port Jackson,Aust .).
1985 : 225 fig.6 ,3D Suruga Mexio んromis /es 伽 α .Baba , , ), figs ,4D ,5D (Awashima ,
Izumi 1987 : 9− 13 丘 Echizen coast and Bay ); , , gs .( Toyama Bay ). ’ (】 s sp . ; , and Ayukawa Echizen eoast )。 hromodem Takahashi , 1973 9,fig (Kuriya ,
Refer also to :
417 −419 figs − Port Aust . Ohromoderis /e8tiva .Bergh , 1893 : , pl.4, .18 22 ( Jackson , ;
color not known ).
estiva Rudman 1973 : 194 196 Chromodoris / , , , .
−158 且 12G 21 Lord Mexic んromis ノ召s 伽 a .Rudman , 1983 : 155 , gs . , , 23 (N .S.W .,Aust .;
Howe Is.).
Mat θ7iα 1:
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Baba : Two Species of Mexichromis 17
Fig .5 。 Mexichromis/bstiva ク リ ヤ イ ロ ウ ミ ウ シ (Ayukawa , Echi − zen coast 越 前海岸 鮎 川 産) A .Entire animal ,1ength 20 mm 全形 背 面,体 長 20mm ; B .The same amimal from below 同 腹面 . − Le 亡ters for Figs.1 5 記号 , c . spermatocyst 貯精嚢 ;ca . caecum 盲 嚢 ; d . denticles小 歯 ;go . genital orifice 生 殖 門 ;in. intestine 腸 ; is. insemination
duct 授 精 管 ; L . Liver 肝 ; ld. labial disc 唇 盤 ; m . main cusp 主 歯尖 ; mg . mantle gland 外 套膜 腺 ; p , penis 陰茎 ; ph . pharynx 咽頭 ; pr . prostate 前 立 腺 ; r .carmine red 赤 色 (Figs.3,5), red −purple 赤紫 色 (Fig .1) ; ro .
rodlets 唇 盤 の 小棒 ; s . secondary cusp 副 歯 尖 ; t. spermatheca 受 精 嚢 ; tu. oral tube 口 道 ; v . vagina 膣 ; vd . vas deferens 輸 精管 ; w . opaque white 蛋 白色 ; y .yellOW 黄 色.
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18 VENUS: VoL 48, No.1(1989)
Speeimen No. 1. Awashima, Suruga Bay, May 4, 1972, 2 specimens (A and B)
coll. by the Marine Scienee Museum, Tokai Univ., length 25 mm in A and 13 mm in B, the speeimen A was used for the main part of description.
Speeimen No, 2, Kuriya, Echizen coast, Aug. 12, 1966, 1 speeimen coll. by Mr.
T. Abe (Takaoka Senior High School), Iength 18mm,
Specimen No. 3. Ayukawa, Eehizen coast, Aug. 10, 1973, 1 speeimen coll. by
Takaoka Biol. Club, length 20 mm (External body form).
Specirnen No. 4. Tateishi-misaki, Tsuruga Bay, Aug. 7, 1988, 1 specimen eoll,
by Takaoka Biol. Club, length 15 mm,
The Specimens No. 1, No. 3 and No. 4 were photographed by me in color, and
the photos were referred to for description.
DescTiption: The baek is rather closely covered with tubercles of different
sizes. The smaller tubereles are simply eonical. The larger tubercles are more
or less raised and mammiiorm. The branchial plumes, 8-9 in number, are set
in a circle around the anus, The mantle glands vary in number and location
according to specimens. For example, the glands are 8 on the right and 3 on
the left in Specimen No, 1 (A), or the glands are 2 on the right and single on the left in Specimen No. 3. These glands oceur usually in the posterior half
of the mantle on underside. No mantle gland is visible in Specimen No. 4, The ground eolor of the back is slightly yellowish white or pure white. The
larger mammiform tubercles are tinged with earmine red. These earmine red
tubereles are less numerous in nurnber in the young animal than in the adult.
In Specimen No, 1 (B) there oceur dorsally only 10 of these red tubereles. The
smaller tubercles are all colorless. The rhinophere is carmine red on the club
and white en the stalk. The branehial plumes are white with a earmine red
rachis to eaeh plume.
The mantle is edged with a broad band of chrorr).e yellow all around, It is
accompanied with a submarginal opaque white band. The outer yellow band
may happen to be interrupted in some places, but it is not always broken into
a series of yellow marks.
The eolorless foot has a submarginal carmine red band which runs from
either side of the head to the tip of the tail. Sometimes this earmine red band 'tentaeles is confined to each side of the tail. The sole is eolorless. The oral (and
at times the foet-eorners) are tipped with carmine red,
The length ef the oral tube was not measured. The labial disc is cut mid-
dorsally. The rodlets of the disc are deeply bifid at their tips. The radular
formula is 70 × 30.0.30. There is no rachidian plate in eaeh row. The first
lateral tooth bears a single denticle on the inside and 2 to 3 denticles on the
outside of the main cusp. The sueceeding lateral teeth have each 3 denticles
on the outer side of the main cusp. The outermost lateral teeth decrease in
size. In all the lateral teeth the cusps and denticles are relatively strong and
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Baba : Two Species of Mexichromis 19
. More exactly speaking main cusp of each tooth is the strongest pointed , the and the uppermost of the outer denticles is secondary in size to 七he main
cusp . Each ]ateral tooth appears thus 七〇 he apieally bicuspidate. Aves 七ibular gland of 七he genital complex could not be studied . But the
spermatocyst is not so small as in 丑 脚 8 θZo伽 廟 .
Remarks : In the maill color features such as the white body with a yellow
border to 七he mantle and the red tubercles set on 七he dorsum my speci − carmine ,
mens seem very 七〇 estiva with which to be similar Goniodoris プ Angas , 1864
they are specifically identified. However 七his species was unknown of its internal ,
, details from Angas s original description.
’ my assigned specimens 七〇 Angas s Prior to identification, Rudman his
species with the placing of this species in the genus MexichTomis Bertsch,1977
see : and : morphology of ( Rudman , 1983 157 Rudman , 1984 214 ).In the the
radular teeth my speeimens agree with 七hose specimens of Rudman 。 As pointed ’ out by Rudman 1983 : 157 his specimens differed slightly from Angas s type ( ),
specimen and from my specimens in having discontinuous instead of mostly a , ’ ’ continuous , band of yellow to the mantle edge . In both Angas s and Rudman s
specimens an opaque white inner band of the mantle border which occurred ,
distinctly in my specimens was not noted , .
要 約
本 文 は イ 卩 ウ .ミ ウ シ 科 の 属 Mexichromis Bertsch ,1977 に 関 す る 論議 (主 と し て Rudman ,1984 :
− つ 214 216) を 参考 と し て ,口 本産種 に き研 究 し た 。
1,Mexichromis multituberculata (Baba ,1953 ) レ ン ゲ ウ ミ ウ シ (馬 場 )
レ ソ ゲ ウ ミ ウ シ は 体 長 30mm 位 。 背面 は 大小 多数 の 突 起 で 被 わ れ , うち 大 形 の 突 起 は 伸 出 し て 長
コ ブ 円 錐状 又 は 長 乳 房 状 を 呈 し ,頗 る 特 長 的 で あ る 。 但 し こ れ らは 収 縮す れ ば 単 な る 状 と な る 。 ま た
背 両 の 大形 円錐 突 起 の 頂部 は 赤 紫 色 に 染 み ,背面黄 色 の 地 色 と対 比 し て , よ く 目 立 つ ,背而 .周 縁 (外.
套 周 縁 ) は 蛋 白 色 広 帯 の 上 に 赤紫 色 大形 突 起 を 規則 正 し く配列 し ,蛋 自班 と赤 紫 斑 と が 相 交 互 す る 如
レ ン ゲ ウ シ く見 え る 。 触 角 の 頂 部 及 び 鰓 葉 中脈 も赤紫 色 に 染 む 。 足 縁 は 赤紫 色帯 を 巡 らす 。 ウ ミ は 衡 . 舌 の 側 歯 の 歯形 に よ り属 il{Texichromis〔本 属 は 木来 は 東 部太 平 洋 海 域 分 布 の 属 ) に 編 入 さ れ る 。本 文 . レ ン ミ シ の ゲ ウ ウ 材料 は ,京都大 学 瀬 戸 臨海 実 験 所 水 族 館 に よ っ て 同 所 近 傍 か ら 採 集 さ れ た 。和 名 は
の レ ソ ゲ よ 背面 大形 突 起 色 色 彩 に る 。 ・ 2 .Mexichromis festiva(Angas ,1864) ク リ ヤ イ ロ ウ ミ ウ シ (馬場 高橋 )
ク リ ヤ イ ロ ウ ミ ウ シ は 体長 25 mm 。 背 而 は 人 小多 数 の 突起 で .被 わ れ る 。大 形 の 突 起 は 概 ね 低 い 乳
で カ ー ミ ン の 房状 , 頂 部 は 赤 色 ( 色) に 染 ま り, 白色 背 面地 色 に 赤 斑 が 散在 し た よ うに 見 え る 。 触 角
の の ・ 二 頂 部 も 鰓 葉中脈 も 赤 色 。背 面 周 縁 (外 套膜縁) は 黄 色 (外 ) 蛋 白色 (内) の 重 色 帯 を 巡 ら す 。 . 黄 色 帯は 個 所 に よ り .多 少 断 続 す る こ と が あ る 。足部 は 全 長 (又 は 尾 部 に 限 り) 辺 縁 に 赤 色 帯 が縦走 す
ク リ ヤ ロ ウ ミ ウ シ の の ク 卩 ミ る 。 イ は 歯 舌 側歯 歯形 に よ り属 Mexichromis に 人 る 。 口 本産 リ ヤ イ ウ
シ ウ は 文 献 LE 掲 の 種 と 同 定 し た が , こ の 同 定 に は 若干 の 点 が 問 題 と し て 残 る 。 本 文 記 載 の 材料 は 駿
河 湾 淡 島 産 (東 海 大 学 海 洋 科 学 博 物 館 採 集 ) を 主 と し, こ れ に 越 前 海 岸 及 び 敦 賀 湾 (高 岡 生 物 研 究 会 . 採 集) を 加 え る 。和 名 の ク リ ヤ イ ロ ウ ミ ウ シ は 本種 の 標 本 の 最 初 の 採 集 地 越 前海岸 厨 (ク リヤ ) に 因
ん で 呼称 し た 。
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References
Angas, G.F. 1864. Deseription d'especes nouvelles appartenant ti plusieurs genres de mollusques nudibranehes des environs de Port-Jackson (Nouvelle-Galles du Sud), aecompagn6e de dessins faits d'apres nature. J. Conchyl., 12: 43-70, pls. 4-6・ Baba, K. 1953. Three new species and two new records of the genus Ggossodoris from Japan. Publ. Seto Mar. BieL Lab., 3(2) : 205-211. Baba, K. 1985. An illustrated key to the Chromodoridinae genera of Japan (Mollusea: Nudibranchia: Dorididae>. Shells Qnd Sea Life, 17{10): 225-228. Bergh, R. 1893. Ueber einige verkannte und neue Dorididen. Verh. k.k. zool.-bot, GeseU. Wien, 43: 408-420, pl. 4. Bertsch, H, 1977. The Chromodoridinae nudibranchs from the Paeific eoast of Ameriea. Part 1. Investigative metheds and supra-speeific taxonomy. The Veliger, 20(2): 107-118.
Izumi, H. 1987. 0n Mexichromis festiva. Janolus, No. 70: 9-13. (In Japanese) Ruclman, W. B. 1973. Chromodorid opisthobranch Mellusca from the Indo-West Pacifie・ Zool. J. Linn. Soc., 52<3): 175-199. Rudman, W. B. 1983. The Chromodorididae (Opisthobranchia: Mollusca) of the Indo- West Pacifie: Chromodoris splendida, C. aspersa and Hypselodoris ptacida coleur gToups. Zool. J. Linn. Soc., 78(2): 105-173. Rudman, W. B. 1984. The Chromodorididae (Opisthobranehia: Mollusca) of the Indo- West Paeific: a review of the genera. Zool. J. Linn. Soc., 81(2-3) : 115-273. Takahashi, S. 1973. Unidentified nudibranchs. 14. Chromodoris sp. Janolus, No. 28: 9. (In Japanese)
[Received: September 1, 1988]
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