von notho2 am 22.04.2022, 19:54 https://doi.org/10.3897/zookeys.1086.77180 (15. Februar 2022)
Revision der Gruppe "Chloritis delibrata (Benson, 1836)" (Gastropoda, Stylommatophora, Camaenidae)
Autoren
Barna Páll-Gergely, Jonathan D. Ablett, Márton Szabó, Eike Neubert
Abstrakt
Es wurde angenommen, dass Chloritis delibrata (Benson, 1836), bekannt aus dem Nordosten Indiens, drei Sortenformen aufweist, die manchmal als Unterarten bezeichnet werden: C. delibrata var. khasiensis (Nevill, 1877) und C. delibrata var. fasciata (Godwin-Austen, 1875) aus den Khasi Hills, Indien, und C. delibrata var. procumbens (Gould, 1844) aus Dawei in Myanmar. Die reproduktive Anatomie der letzteren Form ist bekannt und stimmt nicht mit denen kontinentaler Camaenidengattungen überein, sondern mit der der neu untersuchten Chloritis platytropis Möllendorff, 1894 aus Thailand. Die letztere Art ähnelt konchologisch Bouchetcamaena huberi Thach, 2018 (Synonym von Helix fouresi Morlet, 1886), der Typusart der Gattung Bouchetcamaena Thach, 2018. So kann Bouchetcamaena vorläufig die gesamte Chloritis delibrata-Gruppe beherbergen, mit Ausnahme von var. fasciata, die aufgrund der zahlreichen rötlichen Bänder auf ihrer Schale auf Burmochloritis Godwin-Austen, 1920 übertragen wird. Die Untersuchung von Muscheln, die im Natural History Museum, London, deponiert wurden, ergab, dass sieben morphologisch unterscheidbare Formen vorhanden sind, die hier als repräsentativ für unterschiedliche Arten akzeptiert werden. Aus Indien werden vier neue Arten beschrieben: Bouchetcamaena foveata Páll-Gergely sp. nov., B. fusca Páll-Gergely sp. nov., B. raripila Páll-Gergely sp. nov. und B. subdelibrata Páll-Gergely sp. nov.
Einleitung
Chloritis (Trichochloritis) delibrata (Benson, 1836) galt als eine variable Kamaenidenart, die ein relativ großes Gebiet von Assam in Indien bis Dawei (= Tavoy) in Myanmar bewohnte (Stoliczka 1871; Gude 1914). Die Entfernung zwischen diesen beiden Standorten beträgt etwa 1500 km Luftlinie. Der letzte Überblick über diese Art wurde vor über einem Jahrhundert in der Fauna of British India von Gude (1914) veröffentlicht, der drei Sorten auflistete: var. khasiensis (Nevill, 1877) und var. fasciata (Godwin-Austen, 1875) aus den Khasi Hills, Indien, und var. procumbens (Gould, 1844) aus Tavoy, Myanmar. Die beiden indischen Sorten wurden in der neuesten indischen Checkliste (Ramakrishna et al. 2010) als Unterart von Chloritis delibrata aufgeführt.
Die Untersuchung von Exemplaren, die Chloritis delibrata und seinen Formen zugeordnet sind, im Natural History Museum, London, ergab, dass mindestens sieben Arten anhand der Form der Schale und vor allem ihrer feinen Skulptur unterschieden werden können. So geben wir hier einen Überblick über die C. delibrata-Gruppe und beschreiben die morphologisch erkennbaren, unterschiedlichen Entitäten als Arten.
Generische Position
Die Chloritis delibrata-Gruppe in ihre entsprechende Gattung zu stellen, erwies sich als Herausforderung. Die Morphologie des Kiefers und der Radularzähne sowie die äußeren Merkmale der Fortpflanzungsanatomie von "var. procumbens" aus Moulmein wurden von Stoliczka (1871) beschrieben [neu gezeichnet von Pilsbry (1894) und in diesem Manuskript (Abb. 1)]. Basierend auf diesen Beschreibungen ist der Penis spindelförmig, der Epiphallus ist länger als der Penis, schlank, zylindrisch, der Retraktormuskel setzt am Penis-Epiphallus-Übergang ein und es gibt ein schlankes, spitzes, mäßig kurzes Flagellum. Wir mussten die mögliche Platzierung der Chloritis delibrata-Gruppe in Chloritis Beck, 1837, Trichochloritis Pilsbry, 1891, und Trachia Martens, 1860, untersuchen, da dieser Artenkomplex zuvor in diese Gattungen eingeordnet worden war, zusammen mit Bellatrachia Schileyko, 2018, Bouchetcamaena Thach, 2018, Burmochloritis Godwin-Austen, 1920, Neotrachia Schileyko, 2018, Planispira Beck, 1837, Satsuma A. Adams, 1868, und Sinochloritis M. Wu & Z. Chen, 2019, die die gleichen oder angrenzende geografische Gebiete bewohnen. Die wichtigsten Merkmale der reproduktiven Anatomie sind in Tabelle 1 zusammengefasst.
Taxonomy and systematics
Camaenidae Pilsbry, 1895
Genus Bouchetcamaena Thach, 2018
Bouchetcamaena Thach, 2018: 65.
Type species
Bouchetcamaena huberi Thach, 2018, by original designation (synonym of Helix fouresi Morlet, 1886 – see Páll-Gergely et al. 2020).
Diagnosis
The shell characters are similar to those of most other Chloritis-like groups. Shell depressed to depressed globular (sometimes with a sunken apex), body whorl rounded, colour uniform with a single peripheral band, shell surface covered by hair scars (pits) of variable density (in some cases these are more or less absent on the last whorl) and deciduous periostracum of variable thickness, aperture rounded to oval/subrectangular, peristome expanded, parietal callus only indicated, umbilicus relatively narrow (narrower than one fourth of the shell’s width).
The genital organs [based on B. procumbens (Stoliczka 1871) and B. platytropis (this study)] are characterized by an elongated penis (spindle-shaped or with slightly swollen proximal end), the absence of a penial verge, a slender, cylindrical epiphallus longer than the penis, a retractor muscle inserted at the penis-epiphallus transition or on the distal end of the epiphallus, and a slender, pointed, elongated flagellum.
Remarks
We only move the few species revised here to this genus. However, several other camaenid species from Southeast Asia may belong to Bouchetcamaena, which will be revealed by future studies.
Bouchetcamaena foveata Páll-Gergely, sp. nov.
http://zoobank.org/768A3926-C993-458D-8D27-CC787DCE6633
Type material
Holotype : Khasia Hills [Meghalaya, India], 183, Assam, coll. Godwin-Austen, NHMUK 20191130/2 (D: 20.5 mm, 9.1 mm, mixed lot with B. fasciatus: NHMUK 20191130/1).
Paratypes : Assam, coll. C. Bosch ex coll. H. Rolle, SMF 297336 (2 paratypes, labelled as delibrata f. major); Assam: Chenapoongu, coll. Jetschin ex coll. Gude 1900, SMF 91157 (2 paratypes); Assam: Khasia Hills, coll. C. Bosch ex coll. H. Rolle ex coll. Schlüter, SMF 297335 (2 paratypes); (1) Khasi Hills, Assam, (2) Burma, A.S. Kennard coll., Acc. No. 1824, NHMUK 20191136/2 (2 paratypes, mixed lot with B. procumbens: NHMUK 20191136/1, the Khasi Hills probably refers to foveata, whereas Burma refers to procumbens); India, NHMUK 1871.9.23.99/2 (1 paratype, mixed lot with B. delibrata: NHMUK 1871.9.23.99/1); India, Laity (?) valley, H.F./W.T. Blanford coll., acc. 1944, NHMUK 20191135 (2 paratypes); Khasi Hills, blue label, 13/II/00, NHMUK 20191140 (2 paratypes, shells corroded by Byrne’s disease); Khasi Hills, NHMUK 1920.1.28.12-13/2 (1 paratype, mixed lot with B. delibrata: NHMUK 1920.1.28.12–13/1); Nemotha, blue label, 7/3/91, NHMUK 20191139 (2 paratypes).
Diagnosis
Shell relatively large, fragile, thin-walled, dorsal side flat or even slightly sunken, colour light yellow to whitish, with a faint peripheral band; hair scars represented as elevated knobs (like strawberry seeds), or even hair scars represented as truncated hairs or short, slender, pointed hairs; aperture oval, umbilicus relatively narrow.
[b]Figure 11.
Bouchetcamaena foveata Páll-Gergely sp. nov., holotype (NHMUK 20191130/2). For positions of close-up images see Fig. 6 (F = DM, G = CA, H: LV, I: PC).[/b]
Description
Shell medium-sized to large, thin-walled; dorsal side flat or even sunken; basic colour light yellowish to whitish, a peripheral band of various thickness present in all specimens, running around the shoulder or the body whorl; protoconch consisting of 1.50–1.75 whorls, finely wrinkled and covered by widely-spaced hair scars reminiscent of strawberry seeds; entire shell consisting of slightly less or more than 3.75–4 whorls, separated by a relatively deep suture; teleoconch very finely and irregularly wrinkled; hair scars (reminiscent of strawberry seeds) widely-spaced, clearly visible on the entire teleoconch; occasionally (near suture, behind expanded peristome, inside umbilicus, etc.) short, slender, pointed hairs remaining; hairs inside umbilicus denser than elsewhere on the teleoconch; aperture oval/subrectangular; peristome strongly expanded and slightly reflected, especially in direction of umbilicus; palatal part with thin, whitish, semi-transparent layer, which allows hair scars of penultimate whorl to be seen; umbilicus open, normally wide, funnel-shaped, peri-umbilical keel blunt.
Measurements
D = 20.3–20.5 mm, H = 9.1–10.5 mm (n = 3).
Differential diagnosis
This new species differs from that which is the most similar, B. delibrata, in having a flatter dorsal side, glossier shell, and deep hair scars on the entire surface. The hair scars of B. subdelibrata sp. nov. are much finer and denser on the entire shell surface.
Etymology
The new species is named after its conspicuously pitted (= foveatus in Latin) surface.
Distribution
All samples with relatively precise localities were collected in the Khasi Hills.
Bouchetcamaena fusca Páll-Gergely, sp. nov.
http://zoobank.org/75255BD2-CBD1-4BA5-B0C0-82DD4E88F5CE
Type material
Holotype : Munipur [India, Manipur], coll. Godwin-Austen, NHMUK 1903.7.1.391/2 (D: 16.8 mm, H: 8 mm, mixed lot with B. delibrata, NHMUK 1903.7.1.391/1).
Paratypes : same data as holotype, NHMUK 1903.7.1.391/3 (1 shell: paratype); Gaziphima, Naga Hills, Munipur frontier line, coll. Godwin-Austen, NHMUK 1903.7.1.385 (2 paratypes); Khasi Hills, coll. Godwin-Austen, no. 183, NHMUK 1903.7.1.381a/2 (1 shell, mixed lot with B. delibrata, NHMUK 1903.7.1.381a/1); Manipur, coll. Godwin-Austen, NHMUK 20191134 (1 shell).
Diagnosis
Shell small to medium-sized, with flat dorsal side or very slightly elevated spire; thick, brown, matt periostracum makes hair scars practically invisible, aperture oval.
Description
Shell small to medium-sized; depressed-globular, dorsal side flat or spire very slightly elevated; body whorl slightly or relatively strongly but bluntly shouldered; colour brownish due to thick, matt periostracum; protoconch consists of 1.5 whorls, finely wrinkled, with short hairs near suture; in some specimens wrinkles only visible in the middle of whorls, whereas in others hair scars (pits) are also discernible; entire shell consisting of 3.75–4 whorls, suture moderately deep; short hairs visible in the suture and inside umbilicus; hair scars practically invisible due to thick periostracum; in one paratype (NHMUK 1903.7.1.391) periostracum of lighter colour around each hair scar on the ventral side, making the density of scars visible; very few hair scars visible at the parietal callus, but to a much lesser degree than in other species; aperture oval/subrectangular; peristome expanded and slightly reflected in direction of umbilicus; palatal part with a very thin, whitish, semi-transparent layer; hair scars not visible beneath parietal callus; umbilicus open, relatively narrow, peri-umbilical keel only very slightly indicated.
Figure 12.
Bouchetcamaena fusca Páll-Gergely sp. nov., holotype (NHMUK 1903.7.1.391/2). For positions of close-up images see Fig. 6 (F = DM, G = CA, H: LV, I: PC).
Measurements
D = 15.3–18.7 mm, H = 7.8–8.8 mm (n = 5).
Differential diagnosis
Bouchetcamaena raripila sp. nov. is most similar to B. fusca sp. nov. in having a relatively small shell, narrow umbilicus and brown periostracum, but it differs in the strong, sparsely standing hair scars. All other Bouchetcamaena species have larger, lighter-coloured shells and a wider umbilicus.
Etymology
The new species is named after its dark (fuscus in Latin) periostracum.
Distribution
Seems to be restricted to Manipur, the Khasi and the Naga Hills (India).
Bouchetcamaena raripila Páll-Gergely, sp. nov.
http://zoobank.org/CE6219D5-7470-43D8-BDC2-D07137D2ED37
Type material
Holotype : Kopanedza, coll. Godwin-Austen, NHMUK 20191131 (D: 15.4 mm, H: 8.1 mm).
Diagnosis
Shell small, with slightly elevated spire; periostracum thick, brown, hair scars (truncated hairs or strawberry seed-like scars) extremely sparsely arranged on the body whorl; aperture oval, almost rounded.
Description
Shell small; depressed-globular, with very slightly elevated spire (low domed dorsal side); body whorl rounded; colour brown due to thick, matt (dull) periostracum, locally worn locally making the nude whitish shell surface visible; protoconch consists of 1.5 whorls, finely wrinkled, with hair scars reminiscent of strawberry seeds; entire shell consisting of 4.25 whorls, suture moderately deep; inside of umbilicus and suture with mamilla-like, relatively densely arranged hair scars; other parts of teleoconch with extremely widely-spaced hairs (truncated, reddish-brown hairs or strawberry seed-like scars, and very few, relatively long, conical hairs); aperture oval, almost rounded; peristome strongly expanded and slightly reflected in direction of umbilicus; palatal part with a very thin, whitish, semi-transparent layer, which allows hair scars of the penultimate whorl to be seen; umbilicus open, narrow, funnel-shaped, peri-umbilical keel blunt.
Figure 16.
Bouchetcamaena raripila Páll-Gergely sp. nov., holotype (NHMUK 20191131). For positions of close-up images see Fig. 6 (F = DM, G = CA, H: LV, I: PC).
Measurements
D = 15.4 mm, H = 8.1 mm (n = 1).
Differential diagnosis
Differs from B. procumbens by having a more rounded shell shape and the last whorl is also more rounded. Most important are the extremely widely-spaced and prominent hair scars. This latter trait distinguishes B. raripila sp. nov. from all other similar species.
Etymology
The name raripila refers to the few hairs/hair scars on the shell surface (rarus: few, pilus: hair in Latin).
Distribution
The new species is known from the type locality only. Kopanedza (also spelled Kopamedza) is situated in the Barail Range, Dafla Hills (India), although its exact locality is unknown (Páll-Gergely et al. 2015b).
Bouchetcamaena subdelibrata Páll-Gergely, sp. nov.
http://zoobank.org/BADF67BD-2D56-40D2-8378-823B52F21352
Type material
Holotype : S. Silhet, leg. Chennell, coll. Godwin-Austen, NHMUK 20191132/1 (D: 17.7 mm, 8.6 mm).
Paratypes : Same data as holotype, NHMUK 20191132/2 (1 paratype); Habiang, Garo Hills, coll. Godwin-Austen 183, ex coll. W. Blanford, NHMUK 1906.1.1.714 (3 paratypes); South Sylhet Hills, coll. W Chennell, NHMUK 1903.7.1.61/2 (1 paratype, mixed lot with B. delibrata: NHMUK 1903.7.1.61/1).
Additional material examined
Same data as holotype, NHMUK 20191132/3 (7 juvenile shells).
Diagnosis
Shell medium-sized, nearly flat, greenish, glossy, entire shell with densely arranged hair scars (mostly hardly visible), aperture oval, peristome not particularly expanded.
Description
Shell medium-sized, rather thin walled; depressed, dorsal side entirely flat (type series), or slightly elevated (Habiang); colour greenish to dark yellowish with an obscure, reddish band just above the blunt keel; protoconch consisting of 1.5 whorls, with densely arranged, clearly visible, knob-like hair scars; entire shell with 3.50–3.75 whorls; separated by a rather deep suture; teleoconch overall glossy, with irregular, fine growth lines, ventral side and edge of body whorl (except for last quarter whorl) covered with densely-arranged hair scars, some hair scars also recognizable on the last quarter whorl, but not regular as on the preceding areas; last whorl of dorsal side dominated by wrinkles, and regular hair scars only visible in areas before the last half whorl; aperture almost rounded, slightly oval; peristome strongly expanded and slightly reflected in direction of umbilicus; palatal part with a very thin, whitish, semi-transparent layer, which allows hair scars on penultimate whorl to be seen; umbilicus open, normally wide, funnel-shaped, peri-umbilical keel blunt, only very slightly indicated.
Figure 17.
Bouchetcamaena subdelibrata Páll-Gergely sp. nov., holotype (NHMUK 20191132). For positions of close-up images see Fig. 6 (F = DM, G = CA, H: LV, I: PC).
Measurements
D = 17.7–19.3 mm, H = 8.6–9.9 mm (n = 4).
Differential diagnosis
Bouchetcamaena delibrata is most similar to the new species, but it is larger, has a more strongly depressed shell, elongated aperture and expanded peristome, and lacks hair scars on the last half whorl. The hair scars of B. delibrata are more widely-spaced than those of B. subdelibrata sp. nov.
Etymology
The specific epithet refers to the most similar species.
Distribution
The new species is known from the Garo Hills (Meghalaya, India), and the neighbouring Silhet Hills to the south.
.jfif.jpg "1461953781480Z3nB4jEtw2IOBh0H (1).jfif.jpg (114.04 KiB) 181-mal betrachtet")