Loki athanus, An & Chen & Paulay, 2020

An, Jianmei, Chen, Ruru & Paulay, Gustav, 2020, Three new species of abdominal shrimp parasites (Crustacea: Isopoda: Bopyridae Hemiarthrinae) from the Indo-West Pacific, Zootaxa 4845 (2), pp. 264-274 : 268-269

publication ID	https://doi.org/ 10.11646/zootaxa.4845.2.7
publication LSID	lsid:zoobank.org:pub:ED92874B-EBFF-4A77-A9C8-B654F30BA28C
DOI	https://doi.org/10.5281/zenodo.4407341
persistent identifier	https://treatment.plazi.org/id/03808789-FFC9-A47A-FFCD-AE70CC3782C7
treatment provided by	Plazi
scientific name	Loki athanus
status	sp. nov.

Treatment

Loki athanus View in CoL n. sp.

Figs 2 View FIGURE 2 , 3 View FIGURE 3

Material examined. Holotype female, ovigerous, 1.06 mm, paratype male, 0.5 mm, UF Arthropoda 18690, Madagascar, Nosy Be, across bay from CNRO complex, off Lokobe Reserve, 1–3 meters, 13.4139°S, 48.3056°E, coll. G. Bakary, H. Bruggemann, F. Michonneau, G. Paulay, and T. Werner, 16 May 2008. Infesting Athanas parvus de Man 1910 ( UF Arthropoda 14367) ( Fig. 2 View FIGURE 2 ). GoogleMaps

Description. Holotype female (UF 18690) length 1.06 mm, head length 0.29 mm, head width 0.35 mm, pleonal length 0.40 mm ( Fig. 3A View FIGURE 3 ).

Head subquadrate, white, with black eyes near anterior margin. Antennulae with two articles, antennae with three articles, without setae ( Fig. 3B View FIGURE 3 ). Barbula with one falcate lateral projection on each side ( Fig. 3C View FIGURE 3 ). Maxilliped without palp, and with short, blunt plectron ( Fig. 3D View FIGURE 3 ).

Pereon yellow. First three pereomeres merged into ring encircling the head. Other pereomeres distinct on short side of the body but fused on long side ( Fig. 3A View FIGURE 3 ). Brood pouch pigmented, swollen, full of eggs, covering entire ventral surface of head and pereon. First oostegite with unadorned internal ridge, with broad notch along posterior margin ( Fig. 3E View FIGURE 3 ). All pereopods of similar size and shape ( Fig. 3F View FIGURE 3 ), with stout ischia and short, blunt dactyli. First two pairs of pereopods clustered near head; other five on short side in line along pereon, while on long side pereopod 3 is near middle of brood pouch, 4, 5 near posterolateral border of brood pouch, and 6, 7 near posterior end of brood pouch.

Pleon of five pleomeres ( Fig. 3A View FIGURE 3 ), first four produced into uniramous lateral plates, with uniramous pleopods, fifth without lateral plates, with divergent pair of uniramous uropods.

Paratype male ( UF 18690 ) length 0.5 mm, maximum width (across pereomere 1) 0.19 mm, head length 0.09 mm, head width 0.15 mm, pleonal length 0.12 mm ( Fig. 3G, H View FIGURE 3 ) .

Head semicircular, with large black eyes near posterolateral margin ( Fig. 3G View FIGURE 3 ). Antennae visible from dorsal view, antennulae and antennae with 3 and 5 articles respectively, terminal articles setose ( Fig. 3I View FIGURE 3 ).

Pereon with first segment fused with head, two to seven distinct laterally, but slightly fused near midline ( Fig. 3G View FIGURE 3 ); with curved margins; first segment widest. Pair of pigmented lines extending from third to seventh pereomere ( Fig. 3G View FIGURE 3 ). All pereopods with short dactyli; first two pereopods slightly larger than others, but similar in structure ( Fig. 3J, K View FIGURE 3 ).

Pleon fused into triangular piece, narrower than last pereomere ( Fig. 3G, H View FIGURE 3 ). Pleopods and uropods absent.

Etymology. The specific name, athanus , refers to the host genus.

Remarks. The present specimens are placed in the previously monotypic genus Loki because the female has 7 pairs of pereopods which on the long side have the following position: first two clustered around the head, third near middle of brood pouch, last four clustered around posterior of brood pouch. It further matches Loki because the fifth pleomere lacks lateral plates and has divergent uropods. The male fits Loki because it has a triangular pleon and the head is completely fused with the first pereomere. The new species differs from L. circumsaltanus Markham, 1972 in the following characters (character states in L. circumsaltanus given in parentheses): female with well-developed lateral plates on pleomere 4 (pleomere 4 with reduced lateral plates on short side, without lateral plates on long side) and with four pairs of uniramous pleopods (three pairs of uniramous pleopods); male with large black eyes (lacking eyes), and with pleon distinctly separated from pereomere 7 (pleon medially fused with pereomere 7). The new species extends the range of Loki from the west Atlantic to the Indo-West Pacific.

UF	Florida Museum of Natural History- Zoology, Paleontology and Paleobotany
CNRO	Centre National de Recherches Oceanographiques
T	Tavera, Department of Geology and Geophysics