A new species of Chicomurex (Gastropoda, Muricidae) from the Saya de Malha Bank, Western Indian Ocean Author Bondarev, I. P. text Ruthenica, Russian Malacological Journal 2023 2023-07-01 33 3 121 127 http://dx.doi.org/10.35885/ruthenica.2023.33(3).4 journal article 10.35885/ruthenica.2023.33(3).4 2307-7336 13177372 0578EDD7-433F-41DB-8308-8EBF4696515F Chicomurex kozlovi sp. nov. ( Figs 2 A–O , 3 A–C ) Zoobank registration: urn:lsid:zoobank. or g: a c t: A 7 B 34 83 5 - F 9 D 8 - 4 BE 1 - B 5 28 - D448632B6F53 Type material: holotype ZMMU Lc-41717, SL 41.5 mm , ( Figs 2 A–E ) ; paratype 1 IBSS collection, ibss.bent.2.Mol. p., SL 33.1 mm , w/o ( Figs 2 F–J ) ; paratype 2 CKE , SL 37.9 mm , ( Figs 2 K–O ) . Type locality: Saya de Malha Bank , Mascarene Plateau , Western Indian Ocean , 11°35.2’S , 61°35.2’E , 200 m depth . Etymology: The species is named after Mr. Eugene Kozlov ( Kaliningrad , Russia ) well known all over the world muricid collector, who donated the paratype 1 to IBSS collection, and provided an opportunity to study and photograph the paratype 2. Diagnosis . Shell biconical, heavy, small to medium size for the genus. Spire rather high with up to 7 convex, moderately shouldered teleoconch whorls, suture adpressed. Axial sculpture of third to seventh whorls with 3 rounded, high varices and high intervarical ribs. Spiral sculpture of subsutural ramp of last whorl consists of primary, secondary and few tertiary cords.Aperture broadly ovate, white, light lavender inside. Siphonal canal relatively short, broad, more or less dorsally bent at tip, narrowly open, with 3 long spines more or less strongly dorsally bent. Four first teleoconch whorls pink crimson or dull light crimson. Other teleoconch whorls white, cream-white or light tan with pinkish and light brown tenting between varices. Three chestnut spiral interrupted bands: traced by spots on suture under intervarical ridges, also apparent on varices. Operculum reddish-brown, ovate, with terminal nucleus. Description. Shell biconical, heavy, squamous, nodose, small to medium sized for the genus: from 33.1 mm ( paratype 1) up to 41.5 mm in length ( holotype ) at maturity. Spire rather high with up to 7 convex, moderately shouldered teleoconch whorls ( paratype 2), suture adpressed. First whorl of teleoconch damaged in the holotype and absent in paratype 1. Protoconch unknown. Axial sculpture of two first teleoconch whorls consisting of high, narrow, nodose ribs, third to seventh whorls with 3 rounded, high varices with short, open spines increasing in length, more webbed abapically, and high intervarical ribs: 3 or 4 on third and fourth whorls, 2 or 3 on fifth and sixth, 1 or 2 on last whorl, highest axial knobbed ridge between penultimate and apertural varix. Spiral sculpture of subsutural ramp of last whorl consists of primary, secondary and few tertiary with adis, IP, abis cords, followed by P1, s1, P2, s2, P3, s3, P4, s4, P5, s5, P6, s6, t on convex part of whorl, separated with smooth interspace from ADP. Primary cords extending on varices as short, broad, squamous, weakly adapically recurved open spines, increasing in strength and length abapically. Apertural varix broad, ventrally strongly squamous. Aperture broadly ovate, columellar lip narrow, smooth, weakly broader abapically, rim adherent, weakly erect abapically. Outer lip weakly erect, crenulated, lirate within. Siphonal canal relatively short, broad, more or less dorsally bent at tip, narrowly open, with 3 long ADP, MP, ABP spines and abs ( Fig. 3 B, C ); ADP more strongly and MP less strongly dorsally bent, ABP widest and trilobate in holotype ( Fig. 3B ). FIG. 2. Chicomurex kozlovi sp. nov. : A–E . Holotype ZMMU, 41.5 mm: ventral (A) dorsal (B), right (C), left (D) and apical (E) views; F–J . Paratype 1 IBSS, 33.1 mm: ventral (F) dorsal (G), right (H), left (I) and apical (J) views; K–O . Paratype 2 CKE, 37.9 mm: ventral (K) dorsal (L), right (M), left (N) and apical (O) views. РИС. 2. Chicomurex kozlovi sp. nov. : A–E . Голотип ZMMU, 41,5 мм, ракурсы: вентральный (A) дорсальный (B), справа (C), слева (D), апикальный (E); F–J . Паратип 1 IBSS, 33,1 мм, ракурсы: вентральный (F) дорсальный (G), справа (H), слева (I), апикальный (J); K–O . Паратип 2 CKE, 37,9 mm: ракурсы: вентральный (K) дорсальный (L), справа (M), слева (N), апикальный (O). Four first teleoconch whorls crimson-pink ( holotype and paratype 1) or dull light crimson ( paratype 2). Other teleoconch whorls white, creamy white ( holotype and paratype 1) or light tan ( paratype 2) with pinkish and light brown tenting between varices. Three chestnut spiral interrupted bands: traced by spots on suture under intervarical ridges, also apparent on varices on (adis), IP, (abis), P1, on (s3), P4, (s4) and s6, t6. Aperture white, light lavender inside. Operculum reddish-brown, ovate, with terminal nucleus. Radula unknown. Distribution. Saya de Malha Bank, Mascarene Plateau , Western Indian Ocean , in 100–200 m . FIG. 3. Chicomurex kozlovi sp. nov. , dorsal view with arrows indicating the details of the spiral sculpture: A. Holotype, 41.5 mm, B–C . siphonal canal, enlarged without scale: B – holotype, C – paratype 1. РИС. 3. Chicomurex kozlovi sp. nov. , дорсальный вид с укаЗанием стрелками деталей спиральной скульптуры: A . Голотип, 41,5 мм, B–C . сифональный канал, увеличен беЗ масШтаба: B – голотип, C – паратип 1. Remarks. Many Chicomurex species have a paucispiral protoconch [ Houart et al ., 2021 ], which indicates the absence of a planktonic stage in development and, consequently, results in provincialism and endemism. Since Chicomurex kozlovi sp. nov. has not been found outside the Saya de Malha Bank, it is possible that its protoconch is paucispiral. The brightly colored crimson-pink apical whorls make it distinguishable from other Chicomurex species , and the shell morphology features provide additional evidence. Five additional species of Chicomurex live in the western Indian Ocean: C. gloriosus (Shikama, 1977) , C. laciniatus (Sowerby II, 1841) , C. rosadoi Houart, 1999 , C. vaulberti Houart & Lorenz, 2020 and probably C. turschi (Houart, 1981) [ Houart et al. , 2021 ] ( Fig. 4 ). Chicomurex gloriosus from Madagascar , Reunion and Mauritius and Nazareth Bank in the Indian Ocean and several records in the Pacific Ocean is larger, exceeding 60 mm in length vs. up to 41.5 mm in C. kozlovi sp. nov. , with a distinctly longer siphonal canal but without abs cord. The columellar lip in C. gloriosus has weak folds on its entire length while it is smooth in C. kozlovi sp. nov. Chicomurex gloriosus is pink or light orange, occasionally with a darker spiral band, usually between s2 and s4 or P5 [ Houart et al. , 2021 , Fig. 9 F–S]. Chicomurex laciniatus distributed from Southern Africa, throughout the Indo-West Pacific, to the Fiji Islands is a highly distinctive species because of its light brown, occasionally orange or pale brown color, with darker colored varices, and violet or pink columellar lip [ Houart et al. , 2021 , Fig. 10 A–N]. It has a larger adult size (up to 77 mm ), and lower axial nodes. The spiral sculpture has occasionally an additional tertiary cord (t) above adis, IP on the subsutural ramp and another occasional tertiary cord below P6 and s6 on the convex part of the last whorl. The short or moderately long siphonal canal lacks the abs cord. Chicomurex rosadoi from South Mozambique also has a whitish colored form with pink spire whorls [ Houart et al. , 2021 , Fig. 14 M, N], being mostly light tan to tan with darker colored blotches on the varices [ Houart, 1999 ; Houart et al. , 2021 , fig. 14. J, K, O, P]. Chicomurex rosadoi differs by the longer siphonal canal and a less developed spiral sculpture: (s1)… (s6), few tertiary cords on convex part of whorl, and ADP, MP, ABP extending as small, open spines vs. distinct s1 … s6 followed by rather strong t, and ADP, MP, ABP extending as long dorsally bent spines. FIG. 4. Chicomurex species in the same scale, comparative specimen pictures extracted from [ Houart et al., 2021 ]. РИС. 4. Виды Chicomurex в одном масШтабе, иЗображениЯ сравниваемых ЭкЗемплЯров Заимствованы иЗ [ Houart et al., 2021 ].. Chicomurex turschi is doubtfully reported from Zululand, South Africa , Madagascar and the Philippines , but occurs in Papua New Guinea , south of New Caledonia , Fiji and Tonga , in 45–79 m [ Houart et al. , 2021 ]. It differs by the more slender fusiform shell with less squamous and narrower axial varices, with a longer siphonal canal, lower and more numerous axial ridges: 3 or 4 vs. 2 or 3 on penultimate whorl, 2 or 3 vs. 1 or 2 on the last whorl. Chicomurex turschi spiral sculpture with occasional s5 vs. distinct s 5 in C. kozlovi sp. nov. , and 2 or 3 tertiary cords between s6 and ADP vs. one very prominent tertiary cord followed by smooth space ( Fig. 3A ). Chicomurex turschi is more uniformly clored: cream or light brown, occasionally entirely white or orange, never with distinctly crimson-pink spire whorls. Chicomurex vaulberti , known only from Northern Mauritius , differs in having a lower spire, a broadly convex, less shouldered body whorl and a longer siphonal canal. The spiral sculpture has no abis cord, but two threads on convex part of whorl below s6 vs strong tertiary cord. The spire whorls are whitish vs. crimson-pink or dull pale crimson in C. kozlovi sp. nov. Chicomurex globus Houart, Moe et Chen, 2015 , particularly the West Pacific creamy-white color form ( Fig. 4 ), is most similar to C. kozlovi sp. nov. It differs by the globose, broader and lightly built shell, the narrower siphonal canal, two additional tertiary cords below s6 vs. one strong tertiary cord on the convex part of whorl; the ABP spine is short and narrow vs. long and broad.