Saturday, September 3, 2022

[Invertebrate • 2022] Eunice dharastii • A New Species of Giant Eunice (Annelida: Polychaeta: Eunicidae) from the east coast of Australia

 

Eunice dharastii 
Zanol & Hutchings, 2022


Abstract
A new giant species is described from New South Wales, Australia. Eunice dharastii sp. nov. differs from described Australian species and is most similar to E. aphroditois (Pallas, 1788), E. flavopicta Izuka, 1912, and E. kinbergi Ehlers, 1868. The unique combination of features that characterizes the new species is irregular articulated prostomial appendages; antennae reaching back beyond chaetiger 4; branchiae starting at chaetiger 10, initially button-shaped and distinctly longer than notopodial cirri where best developed; dorsal fleshy knobs on anterior chaetal lobes; notopodial cirri pendulous, abrupt tapering from inflated bases; bidentate compound falcigerous chaetae with both teeth directed laterally, distal tooth much shorter than proximal tooth in median and posterior chaetigers; and dark bidentate subacicular hooks starting at chaetiger 58, tapering to a small head with both teeth directed distally, and proximal tooth much larger than minute and spur-like distal tooth. This new species lives in sandy sediments in coastal waters 1–8 m deep. It is highly mobile and not easy to collect, which may explain why it was not described before.

Keywords: Bobbit worm, Eunice aphroditois, Port Stephens, taxonomy

Eunice dharastii sp. nov.
A anterior end of live specimen coming out of its burrow, dorsal view B anterior end of live specimen coming out of its burrow, anterior view C anterior end, dorsal view D anterior end, lateral E anterior end, dorsal view F parapodia, chaetiger 34, anterior view G parapodia from posterior chaetiger of the fragment, anterior view H branchiae and notopodial cirrus, chaetiger 10 I parapodia, chaetiger 4, upper view J parapodia, chaetiger 90, anterior view. br, branchiae; dbl, dorsal buccal lip; dfk, dorsal fleshy knob, vbl, ventral buccal lip. I, J scanning electron microscopy.
C, D holotype AM W.53870 E–J paratype AM W.41747. 
Scale bars: 0.2 mm (I); 1 mm (F, G, H, J); 5 mm (C, D, E).

Eunice dharastii sp. nov

Habitat and specific density: Water depth, 1–8 m, in tubes in coarse sand substrates; also occurs in sandy habitats to the west and east of the type locality in same depth range. Average specific density in Nelson Bay main beach 3.5 ± 0.6 individuals per 30 m2.

Type locality: Nelson Bay Main Beach (...), Port Stephens, New South Wales, Australia.

Etymology: The species is named in honor of Dr David Harasti, who collected the specimens, donated them to the Australian Museum, and first suspected they were a species new to science.


Joana Zanol and Pat Hutchings. 2022. A New Species of Giant Eunice (Eunicidae, Polychaeta, Annelida) from the east coast of Australia. ZooKeys. 1118: 97-109. DOI: 10.3897/zookeys.1118.86448