Page 14 - Chitons_Mollusca_DELL_ANGELO_1998

B. Dell'Angelo, C. Lombardi and M. Taviani
Suborder ISCHNOCHITONINA Bergen- Subgenus Stenosemus Middendorff 1847
hayn 1930
Family ISCHNOCHITONIDAE Dali 1889 lschnochiton (Stenosemus) vanbellei KAAs
Subfamily ISCHNOCHITONINAE Dali 1985, Pl. 2, Figs. 6, 8
1889
Genus Ischnochiton Gray 1847 Selected references:
Subgenus Ischnochiton s.str. 1985 lschnochiton (Stenosemus) vanbellei
Kaas, p. 316, Figs. 55-68
Ischnochiton (lschnochiton) rissoi (P A YRAU- 1990 /schnochiton (Stenosemus) vanbellei
DEAU, 1826) PJ. 3, Fig. 2 Kaas- Kaas and Van Belle, p. 71, Fig. 29
1996 /schnochiton (Stenosemus) vanbellei
Selected references: Kaas - Biondi and Di Paco, p. 19
1826 Chiton rissoi Payraudeau, p. 87, Pl. 3,
Figs. 4- 5 Materia!: st. 283 (Skerki bank, -107 m,
1908 Ischnochiton rissoi Payraudeau - Nier- grab), 14 plates; st. 285 (Skerki bank, -91 m,
strasz, p. 163, Figs. 10-14 grab ), l p late; st. 295 (Skerki bank, -101 m,
1985 /schnochiton rissoi (Payraudeau) - Ga- grab ), 3 plates.
glini, P l. 5, Fig. 5; P l. 6, Figs. 3-4 ( cum syn.)
1990 Ischnochiton (l.) rissoi (Payraudeau) - Remarks: l. vanbellei is a rather rare spe-
Kaas and Van Belle, p. 78, Fig. 32 cies previously recorded from a few Iocali-
1990 lschnochiton rissoi (Payraudeau) - Mif- ties in associati o n with deep-sea (white) co-
sud et al., p. 57, Figs. 8-9 rals. Our records are instead from rhodalgal
1993 Ischnochiton rissoi (Payraudeau) - Gio- sediments of the Skerki bank, a t depths a bo-
vine and Dell'Angelo, p. 162 ve 100 m and deprived of deep-sea corals.
Materia!: st. 84 (Favignana isl., Secca del Ecology: this taxon is confirmed from the
Toro, -62 m, grab), 6 plates; st. 88 (Favigna- white-coral biocoenosis (with Lophelia pertu-
na isl., -36m, grab ), 2 plates; st. 93 (Scuso sa), since Iiving individuals from the Tuscan
bank, -113 m, grab ), 23 plates; st. 254 (Pan- archipel have been consistently found atta-
telleria isl. -44 m, grab ), l spm.; st. 282 ched to coral branches between 200-500 m
(Skerki bank, -113!141 m, dredge), 13 plates; of depth (Biondi and Di Paco, 1996). We
st. 283 (Skerki bank, -107 m, grab ), 6 plates; ignare whether the coral was alive or subfos-
st. 284 (Skerki bank, -97 m, grab ), l plate; st. sil; however, there are records from shallo-
285 (Skerki bank, -91 m, grab ), l p late; st. wer depths (Tuscan archipel, «Secca delle
288 (Skerki bank, -300 m, grab ), l p late; st. Vedove» -160m: Bogi et al., 1989), including
291 (Skerki bank, -70 m, grab ), 4 plates; st. the present one, pointing out that the ecolo-
292 (Skerki bank, -78 m, grab ), 2 plates; st. gie range of this species is not restricted to
295 (Skerki bank, -101 m, grab), 5 plates; st. coral assemblages.
296 (Skerki bank, -38 m, grab ), l spm.; st.
297 (Skerki bank, -45 m, grab ), l spm.
Distribution: Tuscan archipel, Strait of Si-
cily and Mauritania.
Remarks: this species is rather abundant
in our materia). 1t is a common Mediterra-
nean polyplacophoran normally inhabiting
very shallow habitats. Our Iiving-collected Subfamily CALLOCHITONINAE Plate
specimens show a sculpture more subdued 1901
than the typical form. Genus Callochiton Gray 1847
Ecology: lschnochiton rissoi normally Iives Callochiton calcatus DELL'ANGELO and PA-
between 1-5 m adhering to rocky surfaces, LAZZI 1994, Pl. 2, Figs. 5, 7
stones or dead shells; rarely, it is found in
deeper waters, always on hard substrata. Selected references:
1994 Callochiton calcatus D eli' Angelo an d
Distribution: it is a typical Mediterranen Palazzi, p. 15, Figs. 1-12, 14-19, 20B
taxon; records from the Canary islands and 1995 Callochiton calcatus De li' Angelo an d
the Azores need to be confirmed. Palazzi - Basso, p. 364

246