Penicillicaris maldivensis, Huys, Rony & Mu, Fanghong, 2021

Huys, Rony & Mu, Fanghong, 2021, Johnwellsia, a new intertidal genus of Parastenheliidae (Copepoda, Harpacticoida) from the Taiwan Strait, China, including a review of the family and key to genera, Zootaxa 5051 (1), pp. 236-318 : 299

Penicillicaris maldivensis sp. nov.

urn:lsid:zoobank.org:act:54CA1F70-8A1B-4FE7-A1F5-38AF975509B5

Microthalestris littoralis Sars, 1911 sensu Sewell (1940)

This is the first of three sympatric forms encountered by Sewell (1940) in seaweed washings from Addu Atoll in the Maldives. The species differs from its congeners by the armature of P1 exp-3 which consists of three penicillate spines and one long non-geniculate seta (vs two penicillate spines, one geniculate and one non-geniculate setae). The endopod is also much longer than in Pe. pectinimana comb. nov. and Pe. sewelli sp. nov. (unknown in Pe. penicillata sp. nov.), enp-1 being 1.5 times longer than the exopod (vs. 1.15 times). Females can be distinguished by the 9-segmented condition of the antennule (vs 8-segmented), the absence of modified (forcipate) caudal ramus setae IV–V and the elongate P5 exopod (3.8 times as long as maximum width vs at most three times – unknown in Pe. penicillata comb. nov.).

Original description. Sewell (1940): 191–193; Text-fig. 26A–K.

Type material. The dissected female specimen illustrated by Sewell (1940: Text-fig. 26A, C, E–G, I–J)) is here designated as the holotype of P. maldivensis sp. nov. ( ICZN Arts 16.4 and 72.5.6). The species can be differentiated by the characters mentioned in the diagnosis below and those discussed and illustrated by Sewell (1940) ( ICZN Art. 13.1).

Type locality. Maldive archipelago, Addu Atoll ; seaweed washings .

Differential diagnosis. Penicillicaris . Body length 440–560 μm in ♀, unknown for ♂. Antennule 9-segmented in ♀; with four segments distal to geniculation in ♂. Antenna with 2-segmented exopod bearing two setae on exp-1 and one lateral and three apical elements on exp-2. Mandible with two setae on basis; exopod 1-segmented, with two setae. Maxillipedal armature unconfirmed. P1 exp-3 with three penicillate spines and one long non-geniculate seta. P1 enp-1 about 1.5 times length of exopod. Armature pattern of ♀ P2–P4:

P3 endopod ♂ 3-segmented, with apophysis on enp-3, armature pattern [1.1.02 + apo]. P 5 ♀ exopod elongate, about 3.8 times as long as maximum width; proximal half of inner and most of outer margin parallel; with six elements. P5 endopodal lobe ♀ short, extending to about proximal quarter of exopodal length. P5 exopod ♂ 1- segmented, elongate–oval; with seven elements. P5 endopodal lobe ♂ extending to insertion point of proximal inner seta of exopod; with two elements. Caudal ramus setae IV– V of ♀ not inflated near base .

Etymology. The species name refers to the Republic of the Maldives where the type locality is located.

Notes. Sewell’s (1940) illustration of the P3 endopod (his Text-fig. 26H) was inadvertently mislabelled as the P2 endopod. The absence of the inner seta on P1 exp-2 (his Text-fig. 26G) is probably based on an observational error.