Konatopus tridens 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
Neomegamphopidae
Konatopus
Konatopus tridens

description: Konatopus tridens sp. nov.
Figs 9, 10, 11, 32 A
Type locality.
Bocas del Toro, Panama: Crawl Caye, 9.2459°N, 82.1369°W, depth 1–4 m, in sand.
Distribution.
Panama: Bocas del Toro (present study).
Material examined.
Holotype: Panama • 1 ♂, 4.2 mm; Bocas del Toro, Crawl Caye; 9.2459°N, 82.1369°W; depth 1–4 m, in sand; 25 June 2023; K. N. White leg.; USNM 1743958. Paratype: Panama • 1 ♀, 4.7 mm; same station data as for preceding; USNM 1743959. Other material: Panama • 1 ♂ juvenile, 3.0 mm; same station data as for preceding; USNM 1743960.
Diagnosis.
Male gnathopod 1 basis stout, merus with large anterodistal U-shaped excavation, carpus with three triangular anterodistal processes increasing in size distally, with deep U-shaped excavation between two lower processes, propodus subovate with large proximal notch. Pereopod 5 basis length 2.7 × width. Uropod 3 peduncle ~ 0.5 × length of outer ramus.
Description.
Male (holotype, 4.2 mm). Head. Ocular lobe rounded, eye ovate with many small ommatidia. Antenna 1 shorter than antenna 2, peduncle article 2 1.9 × length of article 1 and 3; flagellum setose with aesthetascs. Antenna 2 ~ 1.4 × length of antenna 1, flagellum moderately setose. Maxilliped inner plate with nine apical plumose setae, outer plate lined with long thin setae and six stout setae. Maxilla 1 missing. Maxilla 2 inner plate with row of facial setae, margin lined with dense setae. Upper lip missing. Lower lip rounded, apically setose. Mandibles similar; palp article 3 stout, clavate.
Pereon. Coxae 1 large, subovate; coxae 2–4 subrectangular. Gnathopod 1 carpochelate; basis stout, with row of long facial setae; merus with large anterodistal U-shaped excavation, carpus with three triangular anterodistal processes increasing in size, with deep U-shaped excavation between two lower processes, propodus subovate with large proximal notch; dactylus thick, closing on carpus, marginally setose. Gnathopod 2 subchelate, much smaller than gnathopod 1; basis widened distally, anterior margin with sparse setae, carpus distally setose with one robust anterodistal seta, propodus distally setose with one distal robust seta. Pereopods 3–7 basis and propodus narrow, elongate. Pereopods 3 and 4 dactylus narrow, elongate. Pereopod 5 dactylus short, stout. Pereopods 6 and 7 much longer than pereopod 5; dactylus long, narrow.
Pleon. Epimera 1–3 rounded, with few distal setae. Uropod 1 with interramal spine, peduncle subequal in length with inner ramus, both margins lined with robust setae, with facial row of robust setae; inner ramus 1.1 × length of outer ramus, lined with robust setae, medial margin lined with fine setae, apical margin with three robust setae; outer ramus both margins lined with robust setae, apical margin with four robust setae. Uropod 2 peduncle broken, with several robust setae, medio-distal margin with acute point; inner ramus 1.2 × length of outer ramus, both margins lined with robust setae, medial margin lined with fine setae, apical margin with three robust setae; outer ramus both margins lined with robust setae, apical margin with three. Uropod 3 peduncle 0.5 × length of inner ramus, with two distal robust setae, medio-distal margin with acute point; inner ramus 1.1 × length of outer ramus, both margins with few robust setae, lateral margin lined with fine setae, apical margin with three robust setae; outer ramus bi-articulate, article 1 margins with few robust setae, apical margin with four robust setae, article 2 with one long seta. Telson apical margin slightly concave with acute lateral points, each point surrounded by four robust setae, lateral margins each with two setae.
Female (paratype, 4.7 mm). Similar in all aspects to the male with the exception of the following: Lower lip outer lobes lined with setae; mandibular lobes long, pointed. Maxilla 1 inner plate apical margin lined with bifurcate setae; palp bi-articulate, article 2 apical margin with four bifurcate robust setae and one serrate robust seta, outer margin with fine setules. Gnathopod 1 weakly subchelate, merus, carpus, propodus, and dactylus densely setose, propodus and dactylus lateral margins lined with fine setae. Gnathopod 2 missing.
Etymology.
After the Latin tridens, meaning fork with three tines and referring to the three triangular process on the gnathopod 2 carpus of males of this species.
Ecology and remarks.
This species occurs among sand at depths of 1– 4 m. This species most closely resembles Konatopus tulearensis Ledoyer, 1982 in sharing the male gnathopod 1 stout basis with a subovate propodus with proximal notch. The new species can be distinguished from K. tulearensis based on male gnathopod 1 merus with short acute distal lobe (vs large lobe), carpus with three triangular anterodistal processes increasing in size, lowest process with deep U-shaped excavation (vs 1 process and small excavation), propodus subovate with large proximal notch (vs subrectangular with small proximal notch), and pereopod 5 basis length 2.7 × width (vs 1.3 × width). The new species can be distinguished from all other described Konatopus species based on the shape of the gnathopod 1 carpus: with one large distal subacute process in Konatopus latipalmus Ledoyer, 1979; with one slight distal process in Konatopus paao J. L. Barnard, 1970; and produced into a rounded lobe distally in Konatopus storeyae Myers, 2002. Live specimens are white in color with brown splotches.
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