Description
Dorsal spines (total): 7; Dorsal soft rays (total): 29-30 (usually: 30), all segmented rays unbranched; Anal spine: 1; Anal soft rays: 26-28 (usually: 27), all segmented rays unbranched; Pectoral fin rays: 18-20, upper and lowermost: 3-4 unbranched, all other rays branched; Pelvic fin rays: I, 5; Segmented caudal fin rays: 17; Upper procurrent caudal fin rays: 10-14 (usually: 10); Lower procurrent caudal fin rays: 10-14 (usually: 10); Total caudal fin rays: 37-45; No visible lateral line; Longitudinal scale series: 125-140 (usually: 125); Gill rakers: 6 + 17-18 = 23-24. Body elongate and compressed, depth: 5.0-6.2 (usually: 5.8) in SL, width: 1.6-2.9 (usually: 1.6) in depth; Head: 3.8-5.1 (usually: 4.5) in SL; Snout: 4.6-7.8 (usually: 4.6) in head; Orbit diameter: 2.3-3.1 (usually: 2.4) in head; Bony interorbital space flat, least width: 3.5-5.1 (usually: 3.9) in head; Caudal peduncle short, deeper than long, least depth: 1.8-2.5 (usually: 1.8) in head. Mouth strongly oblique, forming at angle of about 50° to horizontal axis of body; Maxilla reaching a vertical through centre of eye, upper jaw: 2.7-4.3 (usually: 3.4) in head; Upper jaw with an outer row of four to six, widely spaced, moderately large, incurved canines on each side, and a medial band of small villiform teeth that narrows posteriorly; Lower jaw slightly protruding when mouth closed, with three enlarged recurved canines at corner of each side of jaw, more posterior tooth largest, a middle band composed of two to four rows of low villiform teeth narrowing to a single row posteriorly, and an inner pair of enlarged recurved canines at front corner of each side; No teeth on vomer or palatines; Tongue truncate, set far back in mouth. A low median fleshy ridge on top of head from interorbital space to origin of first dorsal fin; No opercular or preopercular spines; Preopercular margin free only ventrally; Upper end of gill opening at or slightly dorsal to level of middle of eye, the ventral end extending to below posterior margin of preopercle; Anterior and posterior nasal pore separated by a distance about equal to half the pupil diameter; Anterior nasal pore small, rounded and terminating in a short fleshy tube; Posterior nasal pore larger, rounded, with little or no rim. No visible lateral line on body; Pores of cephalic lateral line system as described above in generic diagnosis; Scales small, ctenoid posteriorly on body to about posterior third of dorsal fin, cycloid elsewhere, those anteriorly frequently embedded; No scales on head; No median predorsal scales, but embedded scales extend anteriorly on side nape to level of gill opening or slightly beyond; Prepelvic area of thorax with embedded scales; Anterior portion of isthmus naked; No scales on fins except for approximately basal half of caudal fin. First dorsal fin elevated anteriorly, first spine longest: 3.0-3.9 (usually: 3.6) in SL, second and third spines only slightly shorter; Fifth spine: 2.0-3.5 (usually: 2.0) in head; Sixth spine: 2.6-3.9 (usually: 3.2) in head; Spine of second dorsal fin: 2.7-4.0 (usually: 3.6) in head; Penultimate dorsal fin ray usually longest: 1.3-2.7 (usually: 1.3) in head; Caudal fin truncate or weakly emarginate, lobe tips rounded, fin length: 4.3-5.1 (usually: 4.5) in SL; Pectoral fins moderately pointed, middle rays longest: 4.5-6.1 (usually: 4.7) in SL; Pelvic fins separate, their origin directly below pectoral fin base, length: 5.1-7.4 (usually: 6.3) in SL. Max. length: 6.0 cm TL. Depth range: 25 - 100 m.

Color
Snout, jaws, cheeks, preopercle, and postorbital region bright yellow, remainder of head lavender to lilac; Body lavender to lilac, becoming increasingly pale posteriorly toward caudal peduncle; Postorbital yellow marking continuing to anterior first dorsal fin as a sharp streak, becoming increasingly anastomosed and suffused away from the head; Iris bright yellow, dorsal edge sharply capped in metallic purple with a black mark at 1 o’clock position, sometimes continuing onto interorbital space as a short streak; Interorbital region with bright metallic pink triangle, its base originating from middle of interorbital space, narrowing along entire length of predorsal space before terminating at origin of first dorsal fin; First two interspinous membrane spaces on elevated portion of first dorsal fin blue; Adjacent interspinous membrane space between 2nd and 3rd first dorsal fin spines red, sometimes dusky red; Remaining portion of first dorsal fin translucent lavender, often edged in yellow or orange; second dorsal fin pale yellowish green, distalmost edge with a series of bright yellow or orange spots, one in each interradial membrane space, spots sometimes coalescing; Anal fin similar to second dorsal fin, except edged submarginally in bright yellow and bright blue; Distalmost edge of anal fin with a series of bright yellow or orange spots, one in each interradial membrane space, spots sometimes coalescing; Caudal fin pale yellowish green, slightly translucent on outer edge; Pelvic fins pale blue to white, black tipped distally; Pectoral fins transparent.

Etymology
Nemateleotris: from Greek, nema, -atos = thread, filament + the Greek name of a fish, eleōtris, found in the swampy waters of the Nile (Egypt); From the Greek, eleios = who lives in the marshes. The name Eleotris appears for the first time in Déipnosophistes, a compilation of anecdotes and quotations from ancient authors, written by a scholar and grammarian Greek, Athenaeus of Naucratis (about 170-223 AD). In 1763, the Dutch naturalist and collector Laurentius Theodorus Gronovius (1730-1777) used this name to designate a new genus of fish. The authorship of the genre escapes him because his work was rejected by the scientific community of the time. The genre should have returned to the doctor, entomologist and naturalist of Italian culture, Giovanni Antonio Scopoli (1723-1788) but the late recognition of his work made him lose the authorship of the name. Today the genus, Eleotris, is attributed to Bloch & Schneider, 1801.
lavandula: from Latin, lavandula = lavender. Named after the genus of flowering plants which includes the ornamental herb lavender, in reference to its beautiful coloration in life.
Original description: Nemateleotris lavandula Tea & Larson, 2023 - Type locality: Augulupelu Reef, Palau Islands, depth: 28 meters, multiprong spear, W.A. Starck II, 4 March 1972.

Distribution
Western and central Pacific: Yakushima Island (Japan) south to Taiwan, northern Philippines, Micronesia, Melanesia, Great Barrier Reef and New Caledonia.

Biology
Occurs in relatively deep water. Found over small patches of sand, rubble, or hard open bottoms of steep seaward reefs. Frequently occurs in pairs. Monogamous. Feeds on zooplanktons in the water column. Monogamous mating is observed as both obligate and social. Aquarium fish.

Similar species
Nemateleotris helfrichi (Randall & Allen, 1973) - Reported from Southern central Pacific: Society Islands, Austral Islands, Marquesas Islands, Gambier Islands to Cook Islands, Polynesia.

Last udpate: 12, April 2023