Photis probolion Sir & White, 2025, sp. nov.
Creators: name: Sir, Sally J.
name: White, Kristine N.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Photidae
Photis
Photis probolion

description: Photis probolion sp. nov.
Figs 21, 22, 23, 32 G
Photis sp. D: LeCroy 2000: 158, fig. 193.
Type locality.
Bocas del Toro, Panama: Crawl Caye, 9.2502°N, 82.1318°W, depth 5–13 m, among coral rubble.
Material examined.
Holotype: Panama • 1 ♂, 1.4 mm; Bocas del Toro, Crawl Caye; 9.2502°N, 82.1318°W; depth 10–13 m, among coral rubble; 29 June 2023; K. N. White leg; USNM 1743967. Paratypes: Panama • 1 ♂, 1.6 mm; same station data as for preceding; USNM 1743968 • 1 ♀, 1.68 mm; same station data as for preceding; USNM 1743969. Other material: Panama • 5 ♂, 2 ♀; same station data as for preceding; USNM 1743971 • 2 ♂, 4 ♀; Bocas del Toro, Crawl Caye; 9.2502°N, 82.1318°W; depth 5 m, among coral rubble; 29 June 2023; K. N. White leg; USNM 1743970.
Diagnosis.
Male coxa 1 anteroventral angle rounded, without setae. Male gnathopod 2 basis with large anterodistal lobe, lined with stridulating ridges; propodus process at palmar angle long, slender, curved. Male coxae 3 and 4 with stridulating ridges. Uropods 1–3 rami without marginal robust setae. Uropod 3 inner ramus lanceolate, inner ramus 0.2 × length of outer ramus, outer ramus, bi-articulate, article 2 with at least one apical seta.
Description.
Male (holotype, 1.7 mm). Head. Eyes round, circle of dark ommatidia surrounded by light ommatidia, touching anterior margin of ocular lobe. Antenna 1 broken; peduncle article 2 2.3 × length of article 1. Antenna 2 flagellum 7 - articulate. Maxilliped inner plate apical margin with two rows of plumose setae; outer plate with four robust setae, lined with submarginal setae; palp 4 - articulate. Lower lip inner and outer lobes rounded, lined with fine setae. Maxilla 1 inner plate small with one apical seta; outer plate with eight bifurcate robust setae; palp bi-articulate with three apical robust setae and two marginal setae. Maxilla 2 outer plate with eight apical setae; inner plate with five apical and five marginal setae. Mandibles similar, incisors dentate; palp tri-articulate, articles 2 and 3 setose, with some plumose setae. Upper lip rounded with indentation, apically setose on either side of indentation.
Pereon. Coxae sparsely setose, setae short; coxae 1–4 longer than wide; coxae 3–4 with stridulating ridges. Gnathopod 1 subchelate; basis unexpanded, margins with tufts of long setae; carpus 0.1 × length of propodus; propodus palm serrate, lacking robust setae; dactylus minutely serrate. Gnathopod 2 basis with large anterodistal lobe, lined with stridulating ridges; propodus process at palmar angle long, slender, curved. Pereopod 3 merus minutely expanded anteriorly. Pereopod 4 anterodistal margin of carpus with pointed projection, with few setae. Pereopods 5–7 bases rounded, narrowing sequentially. Pereopod 7 significantly longer than pereopods 5 and 6.
Pleon. Epimeron 3 posteroventral corner subquadrate without notch. Uropod 1 peduncle with one distal robust seta, 1.3 × length of inner ramus; inner ramus 1.3 × length of outer ramus, rami lined with minute setules, lacking robust setae. Uropod 2 peduncle 0.8 × length of inner ramus, with one distal robust seta; inner ramus 1.2 × length of outer ramus, lined with minute setules, lacking robust setae. Uropod 3 peduncle 2.0 × length of inner ramus with one apical seta; inner ramus lanceolate, 0.2 × length of outer ramus, bare; outer ramus bi-articulate, article 2 with two apical setae.
Male (paratype, 1.6 mm). Head. Antenna 1 shorter than antenna 2, distal margins with sparse, long setae, flagellum tri-articulate, terminal article minute. Antenna 2 flagellum 4 - articulate, terminal article minute. Pleon. Telson entire, apex subtriangular, with two setae, lateral margins with subacute points.
Female (paratype, 1.7 mm). Similar in all aspects to the male with the exception of the following: antenna 1 5 - articulate; antenna 2 8 - articulate; coxae without stridulating ridges; coxa 1 ventral margin with few short setae; gnathopod 2 basis anterodistal margin unexpanded, without lobe; propodus with reduced distal thumb, lacking triangular process near insertion of dactylus; pereopod 4 basis anterior and posterior margins with long plumose setae, anterodistal margin of carpus without pointed projection.
Etymology.
After the Latin probolos, meaning any projecting or jutting object or prominence and referring to large anterodistal lobe on the basis of the gnathopod 2 of males of this species.
Distribution.
U. S. A.: Florida: Biscayne Bay, Florida Bay (LeCroy 2000); Panama: Bocas del Toro (present study).
Ecology and remarks.
This species occurs among coral rubble at depths of 1.6– 13 m. Panamanian specimens closely resemble Photis sp. D LeCroy, 2000 with the exception of male gnathopod 2 propodus having a small, rounded process near palmar angle and a smaller thumb at palmar angle, which is most likely due to the small size of the Panamanian specimens. Photis probolion sp. nov. most closely resembles Photis longicaudata (Bate & Westwood, 1862) and Photis bronca Jung et al., 2019 in sharing the rounded anteroventral angle on coxa 1 and the large anterodistal lobe with stridulating ridges on gnathopod 2 basis. The new species differs from P. longicaudata in having stridulating ridges on male coxa 4 and in lacking robust setae on uropods 1 and 2 outer rami. The new species differs from P. bronca in lacking setae on coxa 1 and in having uropod 3 peduncle shorter than the inner ramus (vs peduncle longer than inner ramus). Photis probolion sp. nov. can be easily distinguished from all other described Photis species in having a large anterodistal lobe lined with stridulating ridges on the male gnathopod 2 basis, the general shape of the gnathopod 2 propodus, stridulating ridges on male coxae 3 and 4, and in lacking marginal robust setae on uropods 1–3 rami. Live specimens are white, sometimes with faint brown stripes and pink markings, especially on the antennae.
description: Published as part of Sir, Sally J. & White, Kristine N., 2025, Caribbean Amphipoda (Crustacea) of Panama. Part IV: parvorder Caprellidira, pp. 151-205 in ZooKeys 1234 on pages 151-205, DOI: 10.3897/zookeys.1234.145826