Two new species of Diplommatinidae (Prosobranchia) from high mountain of North Taiwan

 

Yen-Chen Lee1 and Wen-lung Wu2

1.      Department of Life Science National Taiwan Normal University

2.      Research Center of Biodiversity , Academia Sinica.

 

Two species of family Diplommatinidae were collected from the mountainous region of North Taiwan . They all belong to genus Diplommatina. After carefully compared with the shell morpho-characters of the allied species, we believe that one should be new species and name as Diplommatina inferocuspis, another should be high altitude new subspecies of Diplommatina taiwanica taiwanica Pilsbry & Hirase, 1905 and name as Diplommatina taiwanica montana.

Key words: Diplommatinidae, Diplommatina, n. sp., North Taiwan .

 

Materials and Methods

Several specimens of diplommatinid snails from the mountainous region of central Taiwan were measured based on the following morphometric items: shell length (SL), shell width (SW), apertural length (APL) and apertural width (APW).

 

Genus Diplommatina Benson, 1849

Subgenus Sinica Moellendorff, 1885

Diplommatina (Sinica) inferocuspis n. sp. (Fig. 1)

 

Shell: Orange color when fresh, afterward become yellow color, solid, dextral winding, whorls 5.5 in number, first 3 whorls conical shape and rapid expanded its diameter till penultimate whorl then contract at body whorl. Protoconch 1.25 whorls, smooth but sculpture with tiny puncture. Teleoconch 4.25 whorls ornamented with moderately closely set riblets at regular interval from first to penultimate whorl, riblets interval are widest on body whorl. Constriction situated almost at the mid of upper callus, weakly arcuated toward the columellar side. Palatal plica short, situated from the edge of upper callous and connected to the constriction. Palatal plica is much shorter than constriction. Callus distinct well extended to the site, very near suture. Aperture vertical, round shape, peristome thick and duplicate, columellar lip subvertical, always angulate at the junction with basal lip. Triangular columellar tooth is visible at lower part of columella.

 

Measurement and type depository

Holotype: SL: 2.04mm , SW: 1.2mm ; APL: 0.94mm , APW: 0.80mm ; NMNS005076-00001, National Museum of Natural Science , Taiwan .

Paratype: SL: 2011mm , SW: 1.29mm ; APL: 0.84mm , APW: 0.84mm ; NMNS005076-00002, National Museum of Natural Science , Taiwan .

 

Etymology

Infer (low) + cuspis (tooth) by its columellar tooth is at lower part of columella.

 

Type locality

 Daguang mountain (達觀山) in Taoyuan County, North Taiwan, 1400 meters in altitude, gathered from grass slope under leaves.

 

Diplommatina (Sinica) taiwanica montana n. subsp. (Fig. 2)

 

Shell: Yellow color, Shell solid, dextral winding, pupoid shape, whorls 4.75 in number, first 3 whorls conical shape and rapid expanded its diameter till penultimate whorl then contract at body whorl. Protoconch 1.3 whorls, smooth but sculpture with tiny puncture. Teleoconch 4.5 whorls ornamented with moderately closely set riblets at regular interval except on penultimate whorl, riblets interval are narrowest on penultimate whorl. Constriction situated at the mid of upper callus or at the position near outer lip, weakly arcuated toward the columellar side. Palatal plica moderately long, about equal length as constriction. Callus distinct well extended and cover half part of the body whorl. Aperture subvertical, round shape, peristome thick and duplicate, columellar lip subvertical, always angulate at the junction with basal lip. Triangular columellar tooth is visible at middle columella.

 

Measurement and type depository

Holotype: SL: 2.22mm , SW: 1.32mm ; APL: 0.90mm , APW: 0.88mm ; NMNS005077-00001, National Museum of Natural Science , Taiwan .

Paratype1: SL: 2.25mm , SW: 1.33mm ; APL: 0.94mm , APW: 0.9mm ; NMNS005077-00002, National Museum of Natural Science , Taiwan .

Paratype2: SL: 2.34mm , SW: 1.50mm ; APL: 0.90mm, APW: 0.80mm ; NMNS005077-00003, National Museum of Natural Science, Taiwan.

 

Etymology

montana means mountain, because this new subspecies was collected from high mountain.

 

Type locality

Daguang mountain (達觀山) in Taoyuan County, North Taiwan, 1400 meters in altitude, gathered from grass slope under leaves.

 

 

Discussion

Base on general shape of these two new species and subspecies are very similar to D. taiwanica taiwanica Pilsbry & Hirase, 1905 distributed in low altitude of North Tawain , but the two new species are all tiny, about 2/3 length of D. taiwanica taiwanica. Besides, mature individuals of the former are duplicated peristome. D. taiwanica montana differ from D. taiwanica taiwanica by its fewer whorls (with 6.5 whorls in D. taiwanica taiwanica), smeller size and well developed upper callous.

D. inferocuspis is somewhat similar to D. pilula Chang & Tada, 1998, but the later is more contract at body whorl and contraction are on the terminal penultimate whorl just behind of peristome.

 

Acknowledgements

The authors wish to appreciate Mr. Tung, Chen-lung and Ms. Wang, chih-hui for their help to collect these species.

 

Reference

Chang, K.M. & Tada, A. 1998. Diplommatina pilula n. sp.  from Taiwan (Prosobranchia: Diplommatinidae). Bulletin of Malacology R.O.C. 22: 7-12.

Pilsbry, H.A. & Hirase, Y. 1905. Catalogue of the land and fresh-water Mollusca of Taiwan ( Formosa ), with descriptions of new species. ANSP, 57: 720-752.

Fig. 1 Diplommatina (Sinica) inferocuspis n. sp. (A) Holotype; (B) Paratype.



Fig. 2 Diplommatina (Sinica) taiwanica montana n. subsp. (A) Holotype; (B) Paratype1 (C) Paratype2.


 

二種北台灣高山產新種芝麻蝸牛

 

李彥錚1‧巫文隆2

 

1.      台灣師範大學生命科學系

2.      中央研究院生物多樣性中心

 

2002年六月在北台灣高山採得二種芝麻蝸牛,經與其他芝麻蝸牛科種類比對之後,發現不盡相同,擬定為新種。二種新芝麻蝸牛扼要描述如下:

 

下齒芝麻蝸牛(新種) Diplommatina inferocuspis n. sp. (Fig. 1)

殼右旋,橘紅色,堅硬,非常微小,前三螺層成錐形,縱肋相當密緻,至體層後縱肋漸鬆散,腔襞位於滑層範圍,殼口略成圓形,軸齒位於軸唇下端。殼高約2mm

 

高山台灣芝麻蝸牛(新亞種) Diplommatina taiwanica montana n. subsp. (Fig. 2)

殼右旋,淺黃色,前三螺層成錐形,體層收縮,縱肋密緻,次體層縱肋最為密緻,腔襞約與緊線同長,殼口略成圓形,軸齒十分發達位於軸唇1/2處。殼高約2mm

 

謝辭:本文得以完成要感謝董振隆先生及王智惠女士在研究採集過程中所提供的協助。

 

arrow
arrow
    全站熱搜

    snailprincekin 發表在 痞客邦 留言(0) 人氣()