Amphiglena seaverae, Tilic & Feerst & Rouse, 2019

Tilic, Ekin, Feerst, Kathryn & Rouse, Greg W., 2019, Two new species of Amphiglena (Sabellidae, Annelida), with an assessment of hidden diversity in the Mediterranean, Zootaxa 4648 (2), pp. 337-353 : 348-351

Amphiglena seaverae n. sp.

( Figures 7 and 8 )

urn:lsid:zoobank.org:act:DD3BDAF5-56E9-4AC4-A6E1-D4913CDDEC59

Type locality: St. Augustine , Florida (29°40’13.8”N 81°12’54.0”W)

Material examined. Holotype: SIO-BIC A9470, a simultaneous hermaphrodite, fixed in formalin and preserved in ethanol, collected from the edge of a small artificial seawater pond at Whitney Marine Lab in St. Augustine , Florida (29°40’13.8”N 81°12’54.0”W), G. Rouse and E. Tilic, April 16, 2018. A second individual was used completely for DNA sequencing (GenBank COI sequence MK 813355 ).

Description: Holotype 3.5 mm long with a 1.3 mm long branchial crown and maximum body width of 0.45 mm ( Fig. 7A ). Crown with 4 pairs of radioles. ( Fig. 7A, B ). Pinnules appear in alternating longitudinal rows of 6–10 on each radiole, all similar in length ( Fig. 7B ). Radioles with palmate membrane. No radiolar flanges ( Fig. 7B ). Body with eight thoracic and 25 abdominal chaetigers ( Fig. 7A ). Ventral basal flanges present. Dorsal pinnular appendages absent. Anterior peristomial ring even in height all around. Posterior peristomial ring collar absent. Red peristomial eyes present ( Fig. 7A ). Thorax longer than wide. Thoracic chaetigers with a single broadly hooded superior chaeta and two paleate inferior chaetae ( Fig. 8A ). Thoracic uncini 4–5 per torus ( Fig. 8C ). Thoracic uncini with a broad breast, shorter than space from breast to main fang ( Fig. 8C ). Thoracic uncini with long handles ( Fig. 8C ). Companion chaetae present, geniculated with a straight shaft and very long mucro. Abdominal neurochaetae in a single row, broadly hooded ( Fig. 8B ). Abdominal uncini breast broad and handles medium. ( Fig. 8D ). Pygidial eyes present. Eggs seen in lower mid-abdomen. Pair of spermathecae present, located at base of dorsal lips with red pigmentation ( Fig. 7A, B ). Simultaneous hermaphrodite. Oocytes present in abdominal segments 10–15 ( Fig 7C ). Sperm present in the posterior abdominal segments.

Etymology: We name this species for Dr. Elaine Seaver in recognition of her contributions to annelid biology. Dr. Seaver is a Professor at the Whitney Laboratory for Marine Bioscience ( UFL), the type locality of this species.

Remarks: A. seaverae n. sp. appears morphologically very similar to A. lindae Rouse & Gambi 1997 from Belize, yet with a p-distance of 0.27 the COI sequences are so diverse that we can clearly identify A. seaverae as a distinct species. This indicates another potential cryptic species complex of Amphiglena in the Caribbean and west- ern Atlantic. A. lindae is described from the shallow intertidal, with coarse sand, filamentous algae and coral rubble. A. seaverae n. sp. is so far only found in an artificial habitat. Future collections from its natural environment will make a comparison of their habitats possible.

Figures

FIGURE 7. Amphiglena seaverae n. sp. (SIO-BIC A9470) Micrographs showing the live holotype. A, habitus, note the bright red pigmentation of the spermathecae in the live specimen; B, Detail of the crown an anterior thorax in the preserved holotype, spermathecae (st) with redish-brown pigmentation; C, posterior abdomen with oocytes (oc) and red pygidial eye spots (arrow heads).

FIGURE 8. Chaetae and uncini of Amphiglena seaverae n. sp. A, thoracic chaetae; B, abdominal chaetae; C, thoracic uncini; D, abdominal uncini.