Chaetozone corona Berkeley and Berkeley, 1941

Dean, Harlan K. & Blake, James A., 2007, Chaetozone and Caulleriella (Polychaeta: Cirratulidae) from the Pacific Coast of Costa Rica, with description of eight new species, Zootaxa 1451, pp. 41-68 : 46-47

Chaetozone corona Berkeley and Berkeley, 1941

Figure 3 A–C.

Chaetozone spinosa corona Berkeley & Berkeley, 1941: 45 -46.

Chaetozone corona: Hartman, 1960:125 ; Hartman, 1961:109 –110; Hartman, 1969:235, Figures 1–3 ; Reish 1968:86; Blake 1996:285 –287, Figure 8.6A–E; Dean 2004:139.

Material Examined. Costa Rica, Golfo de Nicoya. Sta. 4, 9°53'40"N, 84°46'10"W, 40 m, mud, 10 Jul 1980, (1 USNM 080127). Costa Rica, Golfo Dulce. Intertidal, Bahia Golfito, 2 km west of main dock, muddy sand, 8°38' N, 83°10' W, Sep 1986, coll. José A. Vargas (1 HKD).

Both specimens incomplete, first 8.8 mm long and 1.3 mm wide for 35 setigers, second 7.4 mm long by 0.6 mm wide for 35 setigers; anterior body wide, slightly flattened dorsoventrally; with partial cinctures posteriorly. Pygidium absent. Color in alcohol light tan.

Prostomium conical lobe, with pair of small, round, heavily pigmented, dorsolateral nuchal organs at posterior border beneath slightly overhanging peristomium. Peristomium with dorsal crest extending posteriorly to setiger 1; with three asetigerous annulations, first approximately 3× length of two subequal, more posterior annulations, border between second and third annulations not visible dorsally ( Fig. 3 A B). With pair of dorsal tentacles emerging from slightly swollen dorsal lobe on third peristomial annulation; first pair of branchiae emerging posteriorly and slightly lateral to dorsal tentacles from asetigerous segment 1 fused with third peristomial annulation; remaining branchiae emerging from subsequent setigers at postero-dorsal border of notopodia.

Parapodia long, with slightly elevated ridges bearing wide bundles of long, smooth, capillary setae. Notopodia with 6–7 long smooth capillaries anteriorly, accompanied by 1–2 unidentate spines beginning at setiger 8 in both specimens(8–9 in Blake 1996); capillaries emerging as bundle of shorter capillaries and ventral bundle of longer capillaries by setiger 30 ( Fig. 3 C). Neurosetae 6–7 long capillaries accompanied by 1–2 thick yellow spines from setiger 1; three spines accompanied by two capillaries by setiger 25 ( Fig. 3 C). Neuropodia with short, spines, without color in setigers 1–2, becoming larger and amber-yellow, similar to notopodial spines by setiger 3.

Methyl Green staining pattern. Body staining uniformly green; prostomium, peristomium and asetigerous annulations staining dark blue, tip of prostomium and anterior edge of peristomium not staining.

Habitat. Chaetozone corona was found from the intertidal zone to a depth of 40 m in Pacific Costa Rica. Blake (1996) reported this species from 24–119 m off southern California and western Mexico.

Remarks. The specimens agree well with the description of C. corona by Blake (1996). The structures which Berkeley & Berkeley (1941) and Blake (1996) interpreted as eyes are actually pigmented nuchal organs.

Distribution. Chaetozone corona has now been reported from southern California ( USA), western Mexico, and Pacific Costa Rica, both from both intertidal and shallow subtidal sediments.

Figures

FIGURE 1. Chaetozone acuminate sp. nov. A. Lateral view of anterior end B. Dorsal view of anterior end C. Pygidium, dorsal view D. Posterior setiger, anterior view. Scale bars: A – C = 0.1 mm, D = 0.2 mm. a = annulations, no = nuchal organ.

FIGURE 2. Chaetozone cimar sp. nov. A. Lateral view of anterior end B. Dorsal view of anterior end C. Posterior setiger, anterior view D. Pygidium, dorsal view. Scale bars: A – C = 0.2 mm, D = 20 Μm. a = annulations, no = nuchal organ.

FIGURE 3. Chaetozone corona Berkeley & Berkeley, 1941. A. Lateral view of anterior end B. Dorsal view of anterior end C. Posterior setiger, anterior view. Scale bars: A, B = 0.2 mm, C = 20 Μm. a = annulations, no = nuchal organ.