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| Prionotus pictus Victor, 2025 |
A new endemic searobin, Prionotus pictus n. sp., is described from the Galapagos Archipelago in Ecuador. The prior literature generally assumed that all Prionotus searobins in the archipelago were Prionotus miles, discovered by Charles Darwin on San Cristobal (Chatham Island) and described as endemic by Jenyns (1842). However, almost all underwater photographs from the islands, and surprisingly few museum specimens (three out of dozens), prove to be a quite different-appearing and colorful species. The new species is the island sister species to Prionotus albirostris which is found on deeper trawling grounds along the continental shelf, from Baja California to Peru. The second species found in the Archipelago, Darwin's Prionotus miles, is uncommonly observed, rarely photographed underwater, and so far accounts for only a handful of the hundreds of searobins photographed in Galapagos. The COI mtDNA sequence (DNA barcode) of P. miles shows that it is an island sister species of continental Prionotus stephanophrys (4.87% sequence divergent), which it resembles in a number of basic features, in particular the smooth and gently sloping head and body shape and relatively shorter pectoral fins. A review of the original P. miles holotype and other museum specimens show that P. miles has been inadequately described and guidebooks typically amalgamate and combine characters of the two species, and almost all use photographs of P. pictus to illustrate P. miles. Prionotus pictus is distinguished from P. miles (and P. stephanophrys) by a concave, sharply sloped, duck-billed head profile with more prominent head spines; longer, colorful, and prominently spotted pectoral fins; a triangular spinous dorsal-fin outline with the second spine longest following a stout and serrated first spine of almost the same length; no black blotches on the distal fourth or fifth dorsal-spine membranes; thicker, prominently banded, free pectoral (walking) rays; and a variety of head, fin, and body markings. The new species differs from continental P. albirostris in having a rounded snout (vs. squared off) and distinctive colorful and contrasting patterns (hence pictus meaning 'painted'). It is notable that a large, conspicuous, and relatively common new endemic fish species has eluded recognition for this long.
Key words: taxonomy, ichthyology, tropical eastern Pacific Ocean, coral-reef fishes, marine biogeography, gurnard, Painted Searobin, DNA barcoding, Charles Darwin, Leonard Jenyns
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| Prionotus pictus n. sp. Tagus Cove, Isla Isabela, Galapagos Archipelago, Ecuador (Carlos J. Estape). colorful pattern, Galapagos Archipelago, Ecuador (Roger Uzun, shutterstock.com). |
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| Prionotus pictus n. sp. juvenile, Tagus Cove, Isla Isabela, Galapagos Archipelago, Ecuador (Frank Krasovec). newly settled juvenile, Tagus Cove, Isla Isabela, Galapagos Archipelago, Ecuador (William Bensted-Smith). |
Prionotus pictus, n. sp.
Painted Searobin, Gallineta Pintada
Diagnosis. Dorsal-fin rays X,12; anal-fin rays 11; pectoral-fin rays 14 plus three ventral free rays; pelvic-fin rays I,5; first dorsal fin nearly triangular, first three spines about equal in length, second spine longest, first spine slightly shorter, third spine slighly shorter than second, anterior margin of first spine with pronounced serrations; membranes without a black spot or ocellus specifically on fourth or fifth membranes; pectoral fins fan-shaped semicircular when expanded and long, usually reaching to last third of second-dorsal-fin base or beyond when flat (but variable); snout concave, sharply rising, duck-billed profile, eyes protruding well above profile, snout broadly rounded from dorsal view, no prominent rostral extensions or spiny edges to lachrymal plate; nasal cirrus present, about twice length of nasal opening, no supraocular cirrus; mouth relatively small, lower jaw subterminal and without a knob; head with prominent bony plates, ridges and granulations; head spines comprising preocular, postocular, sphenotic, pterotic, parietal, nuchal, opercular, preopercular (without a supplemental spine), and a cleithral (humeral) spine over pectoral fin (rostral, preorbital, and suborbital spines absent and no postfrontal groove); scales ctenoid and small, about 48 pored lateral-line scales, about 94 vertical rows of lateral scales, nuchal and opercular-flap scales present, ventral scales extend forward just past level of anterior insertion of pelvic fins. Color pattern from common brownish orange pattern to blotched in colors varying from brown to red, to a darker, almost black-and-white pattern; often bright orange ventrally; white patches like splashed paint on head and body in individual unique patterns; a line of prominent white spots highlighting some of the pored lateral-line scales; lip markings a variety of spots and bars (not a simple three dark bands on a white background, at front, middle and corner of jaw); pectoral fin with irregular spot pattern, clearest on common color form, with small rounded spots concentrated on fifth through tenth membranes, becoming reticulations on distal lowermost rays; a thick blue margin on lower 10 rays; pectoral-fin base around origin of rays with an irregular pattern (not discrete rounded spots); caudal fin with dark bars, one at base and a distal wide bar often splitting into two (dark fish can have a black striped pattern); free pectoral-fin rays thick and prominently banded. Juvenile with brown mottled color pattern and relatively longer pectoral fins, reaching past end of second dorsal fin. Newly settled juvenile uniform orangish with two prominent black-edged white saddles along dorsal midline in front of and behind soft-dorsal-fin base; gill rakers short spiny tubercles in two rows of 11, inner and outer, on lower limb of first arch.
Etymology. The species name pictus, Latin for painted, refers to the variegated patterns and colors and individual distribution of colors, with white markings as if splashed with paint. The epithet is considered a masculine adjective.
Benjamin C. VICTOR. 2025. Prionotus pictus, A New endemic Species of Searobin from the Galapagos Islands, Ecuador (Teleostei: Triglidae). Journal of the Ocean Science Foundation. 43, 12-38. DOI: 10.5281/zenodo.15596906