Chiridiella ovata is an aetideid calanoid copepod known after female (2.35 mm in length). Species recorded from the Sargasso Sea and the north-eastern Atlantic. Most probably lower meso- upper bathypelagic species.
Female. (Description after Deevey (1974) and Roe (1975) with modifications). Total length 2.35 mm. Cephalothorax 4 times longer than abdomen. A1 reaching genital segment, 23-segmented. Ri A2 is two thirds of Re length, external lobe of Ri2 A2 with 6, internal with 5 long and 2 short setae; coxopodite with 1 seta. Ri2 Md with 4 setae. Mx1 gnathobase with 8 (?) setae, second internal lobe reduced, third with 1 seta, Ri with 4, Re with 3, external lobe with 8 setae. Mx2 of Ch. macrodactyla type, very close to Ch. abyssalis , the only difference - small seta lacking on the third endite (but Roe (1975) mentions presence of this seta). Mxp protopodite with 1 seta in the distal group, Ri1 Mxp with 3 medial setae. Re1 P1 with 1 external terminal spine, external lobe is not developed. P2-P4 with one-segmented Ri and 3-segmented Re with traces of division in P3-P4.
Remarks. Species is very close to Ch. abyssalis , differs in less number of setae on the third internal lobe of Mx1 (1 seta), less number of setae in the distal part of protopodite (1) and less number of A1 segments (23).
The species was found in hauls between 500 and 1500 m (Deevey, 1974) and 1000-1200 m (Roe, 1975). Most possibly lower meso- upper bathypelagic species.
Atlantic Ocean: the Sargasso Sea, the north-eastern part (18°N 25°W) (Deevey, 1974; Roe, 1975).
Type locality: 32°10'N 64°30'W (Deevey, 1974).
The species absent in the collections of the Zoological Institute, Russian Academy of Sciences, St. Petersburg.