Discovery and Characterization of a Bilirubin Inducible Green Fluorescent Protein From the Moray Eel Gymnothorax zonipectis

Since the initial discovery of Aqueoria victoria’s green fluorescence off the coast of Washington’s Puget Sound, biofluorescent marine organisms have been found across the globe. The variety of colors of biofluorescence as well as the variability in the organisms that exhibit this fluorescence is astounding. The mechanisms of biofluorescence in marine organisms are also variable. To fluoresce, some organisms use fluorescent proteins, while others use small molecules. In eels, green biofluorescence was first identified in Anguilla japonica. The green fluorescence in A. japonica was discovered to be caused by a fatty acid binding protein (UnaG) whose fluorescence is induced by the addition of bilirubin. Members of this class of proteins were later discovered in Kaupichthys eels (Chlopsid FP I and Chlopsid FP II). Here, we report the discovery and characterization of the first member of this class of green fluorescent fatty acid binding proteins from the moray eel Gymnothorax zonipectis. This protein, GymFP, is 15.6 kDa with a fluorescence excitation at 496 nm and an emission maximum at 532 nm upon addition of bilirubin. GymFP is 61% homologous to UnaG and 47% homologous to Chlopsid FP I. Here, we report de novo transcriptome assembly, protein expression, and fluorescence spectroscopic characterization of GymFP. These findings extend the fluorescent fatty acid binding proteins into a third family of true eels (Anguilliformes).

Green morays (Gymnothorax funebris) have sedentary ways in mangrove bays, but also ontogenetic forays to reef enclaves

Surprisingly, little is known about basic life history of the largest moray eel species in the Caribbean region, the green moray eel (Gymnothorax funebris). Sixteen eels were captured from the mangrove fringe in multiple bays on St. Croix, USVI, implanted with coded acoustic transmitters, and their movements were tracked for up to 11 months using an array of 37 stationary acoustic receivers. They exhibited high site fidelity in the bays during their residence, using the same general parts of individual bays and did not switch bays except for one individual. There was no relationship between eel size (mean TL = 83 cm, range = 54–126 cm) and home range size (mean area of 95% KUD = 5.8 ha ± 0.7 SE). Most individuals were more frequently detected at night than during the day suggesting greater nocturnal activity. Several of the larger eels (mean TL = 93 cm ± 5.9 SE) showed clear and permanent emigration tracks out of the mangrove estuary to coral reef habitats offshore. For some individuals, these habitat shifts were preceded by exploratory movements away from the eel’s typical home range the night before emigration. All final emigration events took place nocturnally, happened during a single night, and occurred during months from December to May. Mean emigration speed was 3.4 km/h. This study is the first documentation of an ontogenetic habitat shift in moray eels, as well as the first determination of home range size for this species and their site fidelity in mangrove habitats.

A new white-spotted moray eel, Gymnothorax aurocephalus sp. nov. (Muraenidae: Muraeninae) from Andaman Sea, India

Gymnothorax aurocephalus sp. nov. is described herein based on 4 specimens. Three were collected from off Swaraj Dweep Island of Andaman and Nicobar Islands (A&N Islands) from a depth of 125–130 m and one specimen off Interview Island, A&N Islands at a depth of 90 m. This new species is distinguishable from its congeners by the following combination of characters: chocolate brown color overlain with small irregular white spots, golden skin shadings close to rictus; anus slightly before midbody; pointed and serrated jaw teeth; uniserial teeth in jaws and vomer; vertebral formula 7/61/148–149. The species is compared to all its congeners with white spots.

A new short brown unpatterned moray eel Gymnothorax andamanensis (Muraenidae: Muraeninae) from Andaman waters, India

Gymnothorax andamanensis sp. nov., a new short brown moray eel, is described here on the basis of two specimens collected from Port Mout, Port Blair, South Andaman (11.659327°N; 92.696148°E), caught using baited hand-lines in a sandy habitat at a depth of less than 2 m. The species is characterized in having the dorsal-fin origin before the gill opening, pre-anal length 2.1–2.2, jaw pores with black rim, two branchial pores, predorsal vertebrae 3, preanal vertebrae 57 and total vertebrae 135–136, teeth smooth, three large fang-like median intermaxillary teeth, biserial maxillary and uniserial vomerine teeth, and dentary teeth biserial with two teeth in each side in the second row of the dentary. The new species is compared with all 10 short brown unpatterned moray eels known from the world and two from Indian waters.

A new species of white-spotted moray eel, Gymnothorax smithi (Muraenidae: Muraeninae) from deep waters of Arabian Sea, India

A new species of white-spotted moray eel Gymnothorax smithi sp. nov. is described based on three specimens collected from the southeastern Arabian Sea, India. This is the first deep water report of a moray eel from Indian waters from 200 m depth. This new species is distinguishable from its congeners by the following combination of characters: greyish brown body overlain with white spots of irregular shape, dorsal-fin origin anterior to gill opening, anus positioned slightly behind the mid-point of the body, serrated teeth and a unique vertebral count 3–5 /57/130–132. [Zoobank URL: urn:lsid:zoobank.org:act:9554CE07-E9E7-4B4F-95CD-54F2BB26FF28]