Caulleriella dulcensis, Dean, Harlan K. & Blake, James A., 2007

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 : 54-55

Caulleriella dulcensis sp. nov.

Figures 7 E, 8 A–D.

Material examined. Costa Rica, Golfo Dulce. Holotype: intertidal, Bahia Golfito, 2 km west of main dock, muddy sand, 8°38'N, 83°10'W, Sep 1986, ( MCZ 67149). Paratypes: intertidal, Bahia Golfito, 2 km west of main dock, muddy sand, 8°38'N, 83°10'W, Sep 1986, (1 MCZ 67150; 2 UCRMZ 131) (coll: José A. Vargas).

Small species, holotype 4.5 mm long, 0.4 mm wide for 49 setigers; complete paratype ( UCRMZ 131) 2.7 mm long, 0.3 mm wide for 51 setigers. Body narrow, widest anteriorly with crowded segments; body oval in cross section, slightly flattened dorsoventrally. Notopodial and neuropodial setal bundles widely separated in all setigers; notopodial lobe slightly swollen and extending slightly above dorsum, neuropodial lobe low membrane. Pygidium simple disc ventral to anus ( Fig. 8 C). Color in alcohol light reddish-brown.

Prostomiun short, conical, with overhanging peristomium; paired, round nuchal organs at posterolateral margins ( Figs. 7 E, 8A B). Peristomium long, extending anteriorly as hood over dorsum of prostomium; with three annulations, first annulation approximately 1.5× length second and third subequal posterior annulations, third annulation extending posteriorly onto dorsum of setiger 1; all three peristomial annulations with weak dorsal crest, with separation between annulations indistinct dorsally. Dorsal tentacles arising middorsally from posterior margin of third annulation above setiger 1; first branchiae medial to notopodial setal bundle on setiger 1, and on subsequent setigers.

Notopodial setae long, slightly fimbriated capillaries in anterior setigers, notopodial hooks first appearing at setiger 23 in holotype (setigers 12–14 in shorter paratypes), with 3–4 hooks accompanied by 1 or 2 slightly fimbriated capillaries ( Fig. 8 D), increasing posteriorly to 5–6 hooks with 3–4 capillaries. Neuropodial hooks from setiger 1, beginning as single row of three hooks accompanied by 2–3 capillaries, increasing rapidly to 5–6 hooks in subsequent setigers, accompanied by 1–2 capillaries until setiger 23, capillaries absent in subsequent setigers ( Fig. 8 D). Hooks long, bidentate, with apical tooth of notopodial hooks less prominent than those of neuropodial hooks.

Methyl Green staining pattern. Body staining uniformly light green except for prostomium and peristomium.

Habitat. Described from intertidal muddy sand at Golfito in Golfo Dulce.

Remarks: Caulleriella dulcensis sp. nov. is a small species that is readily recognized by the extension of the peristomium over setiger 1. This species shares the presence of ventral hooks from setiger 1 and dorsal hooks from middle body setigers with Caulleriella cristata Blake, 1996 ; Caulleriella lajolla Blake, 1996 ; Caulleriella chilensis Carrasco, 1977 ; and Caulleriella alata ( Southern, 1914) . C. dulcensis sp. nov. differs from C. cristata and C. lajolla in possessing capillary setae along with ventral hooks in anterior setigers. While C. chilensis from Chile also has accompanying ventral capillaries in anterior setigers, its dorsal hooks begin in setigers 32–40 instead of setigers 12–23 as in C. dulcensis sp. nov. Additionally, the hooks of C. chilensis have a mediodorsal crest while those of C. dulcensis sp. nov. do not. C. alata from the Irish coast possesses capillaries along with the ventral hooks along the entire body but the dorsal tentacles emerge from the last peristomial annulation rather than the middle of the first setiger and its hooks are also limbate.

Etymology. This species is named for the collecting site, Golfo Dulce, in southern Pacific coast of Costa Rica.

Figures

FIGURE 7. Chaetozone nicoyana sp. nov. A. anterior end, lateral view B. posterior neuropodial setal bundle, anterior view. Caulleriella cucula sp. nov. C. anterior end, lateral view. D. neuropodial setal bundle, anterior view. Caulleriella dulcei sp. nov. E. anterior end, dorsal view. Caulleriella minuta sp. nov. F. anterior end, lateral view. no = nuchal organ, s = subacicular tooth.

FIGURE 8. Caulleriella dulcensis sp. nov. A. Lateral view of anterior end B. Dorsal view of anterior end C. Pygidial region, dorsal view D. Posterior setiger, anterior view. Scale bars: A, B = 0.2 mm, C = 0.02 mm, D = 0.1 mm. a = annulations, no = nuchal organ.