Cirriformia, Hartman, 1936

Blake, James A. & Dean, Harlan K., 2019, New Species of Cirratulidae (Annelida, Polychaeta) from the Caribbean Sea, Zootaxa 4671 (3), pp. 301-338 : 326-328

Cirriformia sp.

Figure 15

Material examined. Caribbean Sea, Carib 1, R/V Alpha Helix , Panama, in small lagoon between leeward side of Isla Popa and Cayo Ferro, Sta. ND-30-500, 09°12.8ʹN, 82°2.7ʹW, 08 July 1977, dredged, along mangrove bank, depth 1–2 m, 2 specimens ( USNM 1557510 ) .

Description. Complete specimen 3.5 mm long, maximum width 0.6 mm, with 41 setigers; incomplete specimen 7.2 mm long, maximum width 0.7 mm, with 78 setigers. Body thick throughout, with segments subequal. Dorsum rounded, venter flattened with a mid-ventral groove throughout. Color in alcohol gray-brown to light tan, body with a mid-ventral white line.

Prostomium broadly rounded anteriorly, with slightly swollen dorsolateral ridges posteriorly; eyespots absent ( Fig. 15 A–B). Peristomium as long as first six setigers with three annuli; second annulus slightly enlarged dorsally. Paired tentacular filaments present on setigers 3 and 4; on larger specimen those of segment 4 arise from middle of segment dorsal to branchiae, right tentacular filament arises similarly on setiger 3 while filament on left side arises at anterior border of segment; smaller specimen with two pairs of tentacular filaments arising from middle of both setigers 3 and 4. Branchiae from setiger 1, continuing until last few posterior setigers; present just dorsal to notosetae. Notopodia and neuropodia both slightly elevated ridges along the body; neuropodia widely separated from notopodia ( Fig. 15D ).

Setiger 1 notosetae include five long capillaries, subsequent seven setigers with 2–4 long capillaries usually accompanied by a single shorter capillary, all capillaries with fine teeth along one edge; three spines present on setiger 9, subsequently 1–3 spines often accompanied by 1–2 long capillaries or spines appearing without capillaries. Neurosetae begin as 2–3 long capillaries accompanied by 1–2 short capillaries; neuropodial spines begin on setiger 7, one side of body with three spines accompanied by single short capillary, other side with single, reduced, slightly hooked spine accompanied by two long and two short capillaries; following setigers with 2–3 spines, only occasionally accompanied by a single long capillary ( Fig. 15D ). Spines amber in color; notopodial spines shorter, straighter, and sometimes thicker than neuropodial spines; neuropodial spines slightly recurved ( Fig. 15D ).

Posterior end of body with three weakly differentiated asetigerous segments and a rounded pygidial lobe, anus dorsal ( Fig. 15C ).

Methyl Green stain. Body stains uniformly light blue except for the prostomium, the asetigerous posterior segments, and the pygidium.

Remarks. Due to the few tentacular cirri present and the small size of the specimens, it may be that these are juveniles, making it more prudent to regard this as Cirriformia sp. rather than assigning a species identification. Blake (1975) described a 16-setiger juvenile of C. moorei Blake 1996 (as C. spirabrancha ) as lacking tentacular cirri. Wilson (1936) also noted a lack of tentacular cirri at the 25–30 setiger stage of C. tentaculata ( Montagu, 1808) . Tentacular cirri apparently develop at the late juvenile stage and perhaps these specimens of Cirriformia sp. have not yet developed their full complement of cirri. Magalhães et al. (2014) found bidentate hooks in juveniles of their new species, Cirriformia chicoi from Brazil and suggested that the presence of bidentate hooks may be characteristic of multitentaculate cirratulid juveniles. However, Okuda (1946) and Stephenson (1950) have both described juveniles of the genus Cirratulus as lacking bidentate hooks. Blake (1975), as well as Wilson (1936), also noted the first branchiae appear anterior to the first setiger of Cirriformia moorei and C. tentaculata , respectively. Neither bidentate hooks (even in the 72-setiger specimen) or pre-setigerous branchiae occur in Cirriformia sp., perhaps indicating they may be an adult or early adult form. Additionally, juveniles of C. moorei and C. tentaculata had only weakly developed branchiae on the first several anterior setigers whereas the branchiae of Cirriformia sp. extend to posterior setigers, also suggesting these specimens may be adults.

Dean (2012) listed five species of Cirriformia identified in the Caribbean Sea. Of these five, C. chrysoderma is now recognized as belonging in the genus Protocirrineris ( Petersen 1991) and C. filigera and C. melanocantha are both now recognized as belonging in the genus Timarete . Magalhães et al. (2014) reviewed all eight species of Cirriformia in the Atlantic Ocean and presented a table of morphological characters for each. Cirriformia capillaris ( Verrill, 1900) , reported from Bermuda by Verrill (1900) and Hartman (1942), is similar to Cirriformia sp. in the first occurrence of neuropodial spines (setiger 8 in C. capillaris and setiger 7 in Cirriformia sp.) and the posterior neuropodia having mainly spines with only an occasional single accompanying capillary seta. Verrill (1900) did not note the first occurrence of notopodial spines in C. capillaris . Cirriformia sp. differs from C. capillaris in having only single dorsal tentacles on setigers 3 and 4 while in C. capillaris there is a transverse group of three tentacles on each side on setiger 4. Additionally, Verrill (1900) reported that branchiae occurred only rarely in the posterior half of the body in C. capillaris but in Cirriformia sp. they occur on all segments to the posterior end. Verrill (1900) characterized the “buccal” segment as undivided but the peristomium of Cirriformia sp. is finely subdivided into three subequal segments with only weak separations.

Distribution. Collected subtidally at 1–2 m along a mangrove bank in a small lagoon between the leeward side Isla Popa and Cayo Ferro, Panama.

Figures

FIGURE 15. Cirriformia sp. (USNM 1557510):A, anterior end, dorsal view; B, anterior end, left lateral view; C, posterior end, left lateral view; D, posterior parapodium, anterior view.