Checklist of the family Epitoniidae (Mollusca: Gastropoda) in Taiwan with description of a new species and some new records

Abstract Background The family Epitoniidae is a group of small to medium-sized gastropods and occurs globally from the intertidal zone to abyssal seabeds. There are 101 epitoniid species currently recorded from Taiwan. New information Based on our investigations of seashores and fishing ports of Taiwan, a new species and 12 new records of Epitoniidae species are reported. Of the 12 new records, four are new to the East Asian region and two are new records to the Indo-Pacific region. Our results increase the number of Taiwanese Epitoniidae from 101 species to 114 species.


Introduction
The family Epitoniidae is a group of medium to small size gastropods, usually associating with cnidarians (Gittenberger et al. 2000) and found globally from the intertidal zone to abyssal seabeds. However, most epitoniid species are rare, only a few individuals are provided to study, and most are represented only in private collections (Nakayama 2003). Early naturalists such as Sowerby (1844a), Sowerby (1844b), Reeve (1849), Tryon (1887), Clessin (1897), de Boury (1889), Jousseaume (1911) and Jousseaume (1911) reported many new species and described the taxonomy of this family worldwide. In recent decades, a few local fauna have been reported for the Atlantic species (Bouchet andWaren 1986, DuShane 1974), South African species (Kilburn 1985), and Japanese species (Nakayama 2003). Kilburn (1985), in his work on the South African Epitoniidae fauna, stated that 'epitoniid taxonomy remains in a chaotic state, particularly above the species level'. There had been no systematic discussion of the family Epitoniidae in the Taiwan waters and the adjacent area since Kuroda (1941) reported 12 species of this family, including four unidentified species.
Since Kuroda, Hayasaka (1944) reported a new living record Taiwanese species and two fossil species. Lan (1976) and Lan 1999reported a new species (currently recognized as synonym) and one new record from Taiwan. Shih and Wan (1982) illustrated five species, although two were misidentified. Actually, they reported three species, including one new record from Taiwan. Chong (1993) illustrated a new record of a Taiwanese species, and Lai (1998) illustrated the other two additional new records from Taiwan. Su (1999) illustrated nine species including four new records from Taiwan. Lee and Wu (1998) and Lee (2001b) reported an additional six new species, and Lee (2001a) and Lee (2003) illustrated seven new records from Taiwan. Chen and Lee (2007) illustrated nine tiny epitoniids, six of which were new records from Taiwan. From our viewpoint, most of the earlier report epitoniids are misidentified. A recent published work of Taiwan epitoniids (Lee and Wu 2012) solved the scientific name chaos and reported a huge amount of new records epitoniids from Taiwan. However, new species and records are being discovered continually.
In this study, we will report a new species and 12 new records of epitoniids from Taiwan.

Materials and methods
The epitoniids in this study were collected directly from seashores and fishing ports in Taiwan. The specimens were taken back to the laboratory and cleaned for identification. The habitat depth of the epitoniids are based on the fishing grounds of some particular prawns (Yu and Chan 1986) and lobsters (Chan and Yu 1993), which were trawled with the epitoniids. The distributions of epitoniids are based a shrimp boat logbook. The specimens of holotype and paratype of Epitonium (Parviscala) corniculum sp. n. are deposited in the National Museum of Natural Science, Taiwan (NMNS-7035-001~003).

Claviscala subulae Nakayama 2000
Description Dull white, elongated, spiral elevated with 12 whorls (Fig. 1a). Surface with about 16 weak thick and low axial ribs on the body whorl, spiral striae strong, crossed over axial ribs, about 9 in number on the body whorl, with a basal disc. Shell height 11-15mm.

Distribution
This species occurs off Choshi, Boso Peninsula, Japan at 100m deep. In Taiwan, it is trawled at 400 to 500m depth off the Gueishan Island. This species is a new record from the Taiwan waters.

Distribution
This species occurs off Ashizuri Cape, Tosa Bay, Japan. In Taiwan, it is dredged at 200 to 300m depth of Tong-kang waters, the Peng-hu Trench and the Gueishan Island. This species is a new record from the Taiwan waters.  Epitonium (Epitonium) sororastra Kilburn 1985 Description White, small, with 7-9 costae that are thin, erect and continuous (Fig. 2a). The suture and umbilicus are perforated. The spaces between the costae are smooth, and the aperture is oval. Shell height 8-11mm.

Distribution
This species occurs off Sri Lanka. In Taiwan, only some dead specimens were collected on the beach of Lu-tao Island. This species is a new record from the East Asian region.

Description
White, tiny, axial costae strong and incurved, usually 11-12 in number, slightly elevated at the suture to form an angle, interval smooth (Fig. 2b). Umbilicus closed. Shell height about 3mm.

Distribution
The specimen was collected from the Red Sea. In Taiwan, one was found on the beach at Lu-tao Island in 1995. This species is a new record from the East Asian region. Epitonium fauroti Kaicher 1981: No. 3111.

Distribution
The species has been taken off South Australia. In Taiwan, one dead specimen was collected from the beach of Lu-tao Island. This species is a new record from the East Asian region.

Distribution
Type locality: Dredged from Peng-chia-yu water at the depth of 500-600m.

Taxon discussion
This species is similar to the North Atlantic Ocean abyssal species E. babylonium (Fig.  4e,

Distribution
Occurs in the Pacific coast off Sagami Bay to Kii Peninsula at 100m deep. In Taiwan it was dredged at about 500m depth of NE Taiwan waters. This species is a new record from the Taiwan waters.

Distribution
It is found from Boso Peninsula to Kii Peninsula, Japan. It was dredged at about 100m depth of NE Taiwan waters. This species is a new record from the Taiwan waters.

Distribution
It is found from Sagami Bay to Tosa Bat, Japan. In Taiwan, it was collected from the beach of Ho-Mei, Taipei County. This species is a new record from the Taiwan waters.

Description
Small, white, glossy, with 15-20 thin erect costae that are not peaked (Fig. 3a). With spiral cords between the costae. The whorls are convex and the suture is deep, but closed. The umbilicus is closed. The aperture is oval. Shell height is 3mm.

Distribution
Ranging from Iran to Pakistan to the Maldives. In Taiwan, only one dead specimen was found on the beach of Lu-tao Island. This species is a new record from the Indo-Pacific region.

Limiscala maraisi (Kilburn 1985)
Description Shell white, with 14-16 incurved low costae, which are blade-like under the suture (Fig.  3b). Has fine, closed spiral threads between costae. Umbilicus open but narrow. Shell height about 10mm. Similar to Surrepifungium patamakanthini A. Gittenberger & E. Gittenberger, 2005. However, the present species has thicker shell, is smaller in size, and the costae do not form a coronation.

Distribution
This species was original found in Transkei, South Africa. In Taiwan, it was collected on the beach of the Lu-tao Island. This species is a new record from the Indo-Pacific region.

Distribution
This species ranges from Australia, Queensland though Indonesia. It is new records for Taiwan and the East Asian region. In 1999, several specimens were trawled at Taiwan Strait at depths of 20-50m. This species is a new record from the East Asian region.

Discussion
Most species of this family are white or brown in color and have circular apertures. These delicate shells are generally pyramidal or drop-shaped with many axial costae. The paucispiral horny opercula are black or translucent yellow. They are distributed from tidal to great depths in sandy areas in most seas and found on corals or sea anemones, which feed on them (Nakayama 2000, Gittenberger et al. 2000, Gittenberger and Gittenberger 2005. Most epitoniids are protandrous (Robertson 1981), but the ecology of deep water species has not been documented. They have a ptenoglossan radula with a broad expanse of small, sickle-like teeth (Azuma 1971).
Most Taiwanese wentletraps are rare and hard to obtain, even when dead, because of their tiny size or deep water habitat. These small species are difficult to identify because of their overall similarity and few references. The radula is not informative for generic classification, although protoconch morphology has been used to distinguish the genera (Kilburn 1985).
The key characters used to identify epitoniids are costae characters-whether the shell has a basal ridge or is shaped like a conch (Kilburn 1985, Nakayama 2000. The costal characters are more important than others. We focus on the shape of the costae, which includes their thickness, breadth and coiling, and whether the costae are erect or appear serrated, but not the numbers wach specimen has. The microscopically striated sculpture of the spaces between costae is also an important character. Kuroda (1941) listed 6 unidentified species. Three of them have Japanese name. They are キヌイトカケ, キヌメセキモリ and チリメンイトカケ. Their scientific name are Limiscala irregular, Limiscala lyra and Amaea immaculata through the check of Japanese name on the list of Higo and Goto (1993).
Before our investigation, 101 epitoniids species were recorded in Taiwan (Kuroda 1941, Hayasaka 1944, Lan 1976, Lan 1999, Shih and Wan 1982, Chan et al. 1982, Chang 1982, Chong 1993, Lai 1998, Su 1999, Jeng et al. 1994, Jeng et al. 1996, Jeng et al. 1997, Jeng et al. 1998, Jeng et al. 2000, Lee and Wu 1998, Lee 2001a, Lee 2001b, Lee 2003, Chen and Lee 2007, Lee and Wu 2012. Based on our investigations of the coasts and fishing ports of Taiwan and illustrations by previous investigators, a total of 114 species belonging to 23 genera of Epitoniidae are reported in Taiwan. Of these, 12 are new records in Taiwan, including 4 new that are new to the East Asian region, 2 that are new to the Indo-Pacific region and 1 new species.