Ilypnus arayanensis, Schwarzhans & Aguilera, 2024

Ilypnus arayanensis n. sp.

Figure 46j View Fig

Holotype NMB P15847 View Materials ( Fig. 46j View Fig ), Zanclean , Cubagua FM, Venezuela, PPP 3055 .

Etymology Named after the type locality on the Araya Peninsula in Venezuela.

Diagnosis Otolith size 1.15 mm in length. OL:OH = 1.05. Otolith rectangular with rounded angles. Postdorsal

(See figure on next page.)

Fig. 46 a–c View Fig Gillichthys mirabilis Cooper,1864 ,extant; a, c LACM coll. Fitch; b LACM 57250-3, California, Marina del Rey,SL 108 mm. d Gillichthys seta (Ginsburg, 1938) , extant, LACM coll. Fitch, LTF 701207-2, Gulf of California. e Gillichthys caribbaeus n. sp., holotype, NMB P15846,Manzanilla FM, Trinidad, PPP 2670. f Lepidogobius lepidus (Girard, 1858) ,extant, coll. Schwarzhans leg. Fitch. g Typhlogobius californiensis Steindachner, 1879 , extant, coll. Schwarzhans leg. Fitch. h–i Ilypnus gilberti (Eigenmann & Eigenmann, 1889) , extant, LACM coll. Fitch. j Ilypnus arayanensis n. sp., holotype, NMB P15847,Cubagua FM, Venezuela,PPP 3055. k Quietula ycauda (Jenkins & Evermann, 1889) , extant, LACM coll. Fitch. m–n Quietula guamasiae (Jenkins & Evermann,1889) , extant,LACM 680204-1, coll. Fitch, Cabo Tepopa,Sonora, SL 52 and 70 mm. o–p Quietula rueberi n. sp., Manzanilla FM, Trinidad, Cb.1633; o holotype, NMB P15848; p paratype, NMB P678

projection broad, rounded, not protruding. Sulcus small, shallow, slightly forward positioned, with rounded, widened ostium and short, narrow cauda; OL:SuL = 2.5; sulcus inclination angle 12°. No subcaudal iugum. Ventral furrow narrow, close to ventral rim of otolith, curving around sulcus to join narrow dorsal depression.

Description Otolith size 1.15 mm in length (holotype). OH:OT= 2.5. Otolith rectangular with regularly rounded predorsal, postdorsal, preventral and postventral angles. Dorsal rim shallow, with weak, broad, rounded middorsal angle. Postdorsal projection broad, rounded, not protruding. Anterior rim straight, vertical, without concavity. Posterior rim with very small concavity at its middle. Ventral rim slightly curved, horizontal, with broadly rounded preventral angle and rounded, recessed postventral angle. All rims thick in lateral view, slightly undulating.

Inner face convex, smooth. Sulcus small, shallow, droplet-shaped with rounded ostium and narrow, short cauda; sulcus inclination angle 12°; OL:SuL = 2.5. No subcaudal iugum. Dorsal depression narrow, shallow, positioned across middle of dorsal field; ventral furrow narrow, relatively close to ventral rim of otolith, turning around sulcus anteriorly and posteriorly and joining up to dorsal depression. Outer face about as convex as inner face, smooth.

Discussion Ilypnus arayanensis resembles the extant I. gilberti ( Fig. 46h–i View Fig ) in otolith shape, the small, shallow sulcus, the smooth inner face, and the narrow ventral furrow close to the ventral rim of the otolith and joined to the dorsal depression. It differs primarily from the extant species in the lower dorsal rim and the slightly eccentrically forward-positioned sulcus. Otoliths of the second extant species of the genus, Ilypnus luculentus (Ginsburg, 1938) from the Gulf of California, are not known. Ilypnus gilberti is found on mudflats and shallow bays, and males are known to guard the eggs ( Froese & Pauly, 2023).