Animalia Amphipoda Lysianassidae WhiteKristine N.Caribbean Amphipoda (Crustacea) of Panama. Part III: parvorder LysianassidiraZookeys24102024121614917110.3897/zookeys.1216.135258 5477E6BE-8893-5CF9-B18C-DA17F10A7295 Orchomenella thomasi Lowry & Stoddart, 1997Figs 9, 11D Orchomenella thomasi Lowry & Stoddart, 1997: 109–113, figs 52–53; LeCroy 2007: 586, fig. 502.Material examined.

Panama • 1.5 mm • 1 ♀; Bocas del Toro, Cayo Zapatilla 1; 9.2700°N, 82.0587°W; depth 10–11 m, among coral rubble; 28 June 2023; K.N. White leg.; USNM 1739787.

Diagnosis.

Head ocular lobe subtriangular. Gnathopod 1 carpus shorter than propodus. Epimeron 3 posteroventral corner acute. Urosomite 1 with dorsodistally acute carina. Uropod 3 inner ramus bare; outer ramus 2-articulate.

Distribution.

USA: from Sanibel Island, Florida to Louisiana (Lowry and Stoddart 1997; LeCroy 2007); Panama: Bocas del Toro (present study).

10.3897/zookeys.1216.135258.figure90A6D1DDD-AA0E-5ACE-A9F2-528921A14B8C

Orchomenellathomasi, female, 1.5 mm, head, epimeron 3 and urosome, gnathopod 1 lateral. Scale bars: 0.5 mm.

https://binary.pensoft.net/fig/1160285Ecology and remarks.

These amphipods are associated with sand and coral rubble at depths of 10–73 m. Panamanian specimens closely resemble previously described specimens. Panamanian specimens are white in color when alive.

10.3897/zookeys.1216.135258.figure10AFB840BC-677F-572F-8152-B742EB1926D0

Photographs of live specimens unless noted AArugaholmesi (ethanol preserved specimen) BBonassabonairensisCConcarnesconcavusDLysianopsishummelinckiELysianopsisozona. Scale bars: 1.0 mm.

https://binary.pensoft.net/fig/116028610.3897/zookeys.1216.135258.figure11A5220653-23AF-5681-9140-C43AF47F66BE

Photographs of live specimens unless noted AShoemakerellacubensis (ethanol preserved specimen) BShoemakerellalowryiCLepidepecreummagdalenensis (ethanol preserved specimen) DOrchomenellathomasi (ethanol preserved specimen). Scale bars: 1.0 mm.

https://binary.pensoft.net/fig/1160287LeCroySE (2007) An Illustrated Identification Guide to the Nearshore Marine and Estuarine Gammaridean Amphipoda of Florida Volume 4: Families Anamixidae, Eusiridae, Hyalellidae, Hyalidae, Iphimediidae, Ischyroceridae, Lysianassidae, Megaluropidae, and Melphidippidae. Florida Department of Environmental Protection Annual Report Contract No. WM724 1: 1–195.LowryJKStoddartHE (1997) AmphipodaCrustacea IV. Families Aristiidae, Cyphocarididae, Endevouridae, Lysianassidae, Scopelocheiridae, Uristidae.Memoirs of the Hourglass Cruises10: 1–148.