Ascidiella aspersa ( Müller, 1776 )

Pyo, Jooyeon, Lee, Taekjun & Shin, Sook, 2012, Two newly recorded invasive alien ascidians (Chordata, Tunicata, Ascidiacea) based on morphological and molecular phylogenetic analysis in Korea *, Zootaxa 3368 (1), pp. 211-228 : 215-219

publication ID	https://doi.org/ 10.11646/zootaxa.3368.1.10
persistent identifier	https://treatment.plazi.org/id/03B587A1-FFE6-086A-FF03-532C0B65912F
treatment provided by	Felipe
scientific name	Ascidiella aspersa ( Müller, 1776 )
status

Treatment

2. Ascidiella aspersa ( Müller, 1776)

( Figs. 2B View FIGURE 2 , 3C–D View FIGURE 3 , 4 View FIGURE 4 , Table 3)

Ascidia aspersa Müller, 1776: 72 View in CoL , fig. 2.

Ascidiella aspersa: Berrill, 1928: 170 ; Millar, 1952: 43; Currie et al, 1998: 24; Stachowicz et al., 2002: 15497; Picton & Morrow, 2010a: ZD1410; Sanamyan & Monniot, 2011b: 103718; NIMPIS, 2012: 6000005711.

: C. lepadiformis View in CoL ,: A. aspersa ,: C. intestinalis View in CoL ,: M. manhattensis View in CoL ,: S. plicata View in CoL .

Materials examined. 12 individuals., Daejin , 17 Oct. 2010, Shin S, ropes at 2.7 m depth ; 9 inds., Ayajin , 17 Oct. 2010, Pyo J, ropes at 2.7 m depth ; 5 inds., Namae , 18 Oct. 2010, Shin S, dock wall at 1.7 m depth ; 15 inds., Bangeojin , 20 Oct. 2010, Shin S, ropes at 2.7 m depth ; 4 inds., Jangsaengpo , 20 Oct. 2010, Lee T, dock wall at 2 m depth ; 8 inds., Daebyeon , 20 Oct. 2010, Pyo J, dock wall at 3 m depth ; 19 inds., Tongyeong , 21 Oct. 2010, Pyo J, fish trap at 3.3 m depth ; 17 inds., Gunsan , 22 Oct. 2010, Lee T, fish trap at 2.5 m depth ; 27 inds., Daejin , 22 June 2011, Lee T, ropes at 1.3 m depth ; 13 inds., Gonghyeonjin , 22 June 2011, Pyo J, ropes at 2.7 m depth ; 7 inds., Ayajin , 22 June 2011, Pyo J, thick cloth at 1.5 m depth ; 43 inds., Yangpo , 24 June 2011, Shin S, ropes at 2.1 m depth ; 16 inds., Gampo , 24 June 2011, Shin S, thick cloth at 1.2 m depth ; 9 inds., Bangeojin , 25 June 2011, Shin S, ropes at 2.7 m depth ; 8 inds., Jangsaengpo , 25 June 2011, Lee T, fish trap at 2.3 m depth ; 52 inds., Daebyeon , 25 June 2011, Pyo J, dock wall at 3 m depth ; 8 inds., Busan, 25 June 2011, Pyo J, under floating dock at 0.2 m depth ; 424 inds., Tongyeong , 26 June 2011, Pyo J, dock wall at 2.5 m depth ; 21 inds., Gwangyang , 26 June 2011, Shin S, fish trap at 3.3 m depth ; 12 inds., Mokpo , 26 June 2011, Lee T, fish trap at 2.5 m depth ; 19 inds., Gunsan , 27 June 2011, Shin S, under floating dock at 0.3 m depth ; 22 inds., Incheon, 27 June 2011, Lee T, ropes at 1.8 m depth ; 23 inds., Daejin , 16 Oct. 2011, Lee T, ropes at 1.3 m depth ; 5 inds., Chodo , 16 Oct. 2011, Shin S, dock wall at 1.5 m depth ; 3 inds., Geojin , 16 Oct. 2011, Shin S, ropes at 1.8 m depth ; 19 inds., Gonghyeonjin , 16 Oct. 2011, Pyo J, ropes at 2.7 m depth ; 7 inds., Ayajin , 16 Oct. 2011, Lee T, thick cloth at 1.5 m depth ; 8 inds., Namae , 17 Oct. 2011, Shin S, ropes at 2.1 m depth ; 14 inds., Jumunjin , 17 Oct. 2011, Lee T, under floating dock at 0.1 m depth ; 10 inds., Sacheon , 17 Oct. 2011, Pyo J, ropes at 2 m depth ; 13 inds., Gangneung , 17 Oct. 2011, Shin S, thick cloth at 2.1 m depth ; 6 inds., Imwon , 18 Oct. 2011, Lee T, dock wall at 1 m depth ; 13 inds., Guryoungpo , 18 Oct. 2011, Pyo J, dock wall at 3 m depth ; 39 inds., Yangpo , 18 Oct. 2011, Shin S, ropes at 2.1 m depth ; 19 inds., Gampo , 18 Oct. 2011, Shin S, thick cloth at 1.2 m depth ; 5 inds., Bangeojin , 19 Oct. 2011, Pyo J, ropes at 2.7 m depth ; 11 inds., Jangsaengpo , 19 Oct. 2011, Lee T, fish trap at 3 m depth ; 37 inds., Daebyeon , 19 Oct. 2011, Pyo J, dock wall at 1.1 m depth ; 8 inds., Busan, 19 Oct. 2011, Pyo J, under floating dock at 0.2 m depth ; 74 inds., Tongyeong , 20 Oct. 2011, Shin S, dock wall at 2.1 m depth ; 15 inds., Gwangyang , 20 Oct. 2011, Shin S, fish trap at 3.2 m depth ; 8 inds., Mokpo , 20 Oct. 2011, Lee T, fish trap at 2.9 m depth ; 12 inds., Gunsan , 21 Oct. 2011, Shin S, under floating dock at 0.2 m depth ; 24 inds., Incheon, 21 Oct. 2011, Shin S, ropes at 2.8 m depth .

Description. Body heart- or irregular oval-shaped, sometimes covered with debris and fibrils. Tunic firm, thick and rough, grayish color, semi-transparent, and with numerous tiny papillae spread all over surfaces ( Fig. 4L View FIGURE 4 ); visceral organs observed by naked eye on left side. Some pigments of reddish or heavy orange appeared near inside both siphons ( Fig. 4D View FIGURE 4 ). Oral siphon 6–8 lobed, positioned at top of body ( Fig. 4G View FIGURE 4 ). 19–25 slender tentacles located inner rounded orifice and well developed ( Fig. 4I View FIGURE 4 ). Long tentacle and short one irregular arranged and longer ones outnumber shorter ones. Atrial siphon 4–6 lobed, positioned around one third of way down body away from oral siphon ( Fig. 4H View FIGURE 4 ). Both siphons almost frilled, like flute in water. Dorsal tubercle U-shaped and with horns incurved ( Fig. 4I View FIGURE 4 ). Branchial sac with numerous rows of straight stigmata not folded, located on right side. Body muscles usually form irregular network at mantle covering branchial sac, like string or thread ( Fig. 4D View FIGURE 4 ). Numerous muscles of both siphons well developed. Esophagus positioned right bottom beneath end of pharynx on right side ( Fig. 4F View FIGURE 4 ). Stomach very weak and easily damaged, short, with a longitudinal opaque white line. Intestine has first and second gut loops, located behind branchial sac. Intestinal tract from right bottom on left side, and made first gut loop upwards of half-way of body. Curved intestinal tract runs to bottom and makes second gut loop ( Fig. 4E View FIGURE 4 ). Anus formed at end of extended gut ( Fig. 4K View FIGURE 4 ). Gonads enclosed in first gut loop. Ovary almost fills in first gut loop. Testis surrounds ovary ( Fig. 4E View FIGURE 4 ). Gonoduct at center of first gut loop and extends along close to outside second gut loop, opening with anus near base of atrial siphon ( Fig. 4K View FIGURE 4 ). Numerous eggs crowded at gonads, and scattered all along gut.

Size. Individuals measured up to 83 mm long and usually attached on hard substrates by their left side; usual size is 20–47 mm.

Distribution. Native to Norway. Northeast Atlantic ( Sweden, Baltic Sea, Irish Sea, English Channel, Germany), Mediterranean Sea, South Africa, New England, Argentina, South Australia, Tasmania, New Zealand, Japan, and Korea (East Sea, Korea Strait, Yellow Sea).

Remarks. This species was widespread in three coastlines of Korea except Jeju Island ( Table 3). Some parasitic amphipods were often found in the branchial sac ( Figs. 4F, J View FIGURE 4 ). S. plicata an established alien species in Korea were found attached to a rope and looked like aquacultured organism at Tongyeong yacht marina in October 2010 ( Figs. 3A, B View FIGURE 3 ). But newly introduced A. aspersa occupied the same rope at the same location in June 2011 ( Fig. 3C View FIGURE 3 ). It has been suggested that S. plicata might be replaced by A. aspersa in competition for habitats. As shown in Fig. 3 View FIGURE 3 , the reduction of individual number of S. plicata was considered to be by the loss of food intake due to the attachment of many A. aspersa ( Fig. 3D View FIGURE 3 ). This seasonal change of species needs to be examined continuously.