Chaetonotus (Zonochaeta) cestacanthus Balsamo, 1990

Figs 33–34; Table 6

Chaetonotus (Zonochaeta) cestacanthus Balsamo, 1990: 168, fig. 4.

Locus typicus

Italy.

Material examined

POLAND • 3 adults, 1 juvenile; Kraków, Botanical Garden, Jubilee Greenhouse, sites 1–2; 50°03'38" N, 19°57'30" E; 15 Nov. 2013 and 17 Apr. 2014; M. Kolicka leg.; NHC-GCZC-24-1-10 (photomicrographs, also in the author’s collection) .

Distribution

Chaetonotus (Z.) cestacanthus Balsamo, 1990 was originally described from Italian lakes, namely Lake Chiusi and Lake Bolsena (Balsamo 1990), and next recorded from the volcanic Lake Nemi, also in Italy (Balsamo & Fregni 1995). It has not previously been listed outside of this country.

Remarks

The original description of C. (Z.) cestacanthus is very detailed (Balsamo 1990) and specimens found in the Jubilee Greenhouse in Kraków correspond well with it. However, the present specimens differ from the original data in being slightly larger (Table 6) and in having three pairs of dorsal sensory bristles instead of two (the additional pair arising on the head, near the dorsal cephalion edge); the first scales of the dorsal longitudinal rows, located near the cephalion and epipleurae, are more elongated and have longer spines than the remaining head scales in comparison to the original description and figures (Figs 33–34); the ventrolateral and ventral scales are similar to the dorsal ones (Fig. 33B), and dorsolaterally on the furcal appendages they have one pair of double-keeled scales, rounded in shape, with shallow posterior notches (Fig. 34B).

Chaetonotus (Zonochaeta) cestacanthus has previously been recorded only as an element of benthic assemblages in sandy sediments, as well as in sediments rich in detritus, at a station with rich vegetation (Balsamo 1990; Balsamo & Fregni 1995). There have been no reports of this taxon being found in epiphytic or other periphyton communities, although their presence in samples collected near rich aquatic vegetation may suggest that C. (Z.) cestacanthus could also survive in this habitat type.