Herein, we report the second known specimen of the one‐jaw eel, Monognathus jesse , collected in 4200 m of water, between 1748 and 2001 m depth, in the northeastern Pacific. This specimen is the second‐largest identified monognathid specimen reported, with a total length of 154 mm unpreserved. A morphological description, comparison to the much smaller holotype and similar species, a micro‐computed tomography scan, and mitocho...

With an area covering just under 1 million km 2 , Australia’s Coral Sea Marine Park (CSMP) is among the largest marine protected areas globally. Yet, the demersal deep-reef fish fauna of the CSMP remains poorly described, due in part to its remote location, as well as its sheer size, much of which is inaccessible below conventional SCUBA diving depths. Recent remotely operated vehicle (ROV) explorations conducted by the Schmid...

Gnathophis johnsoni sp. nov. is described on the basis of 15 specimens (138–380 mm TL) from the Emperor–Hawaiian Seamount Chain in the western and central North Pacific. The new species is most similar in morphology to G. bathytopos (Atlantic), G. cinctus (eastern Pacific), and G. smithi (Nazca and Salas-y-Gomez Seamounts in the southeastern Pacific) by the sensory pore configuration and vertebral count, but differs from these...

Although longjaw mudsucker ( Gillichthys mirabilis , Gobiidae) has been studied extensively for its ability to occupy low‐oxygen environments, few studies have addressed the evolution of its exceptionally elongated jaws that extend posteriorly beyond the gill opening in large adults. In this study, the ontogeny of the maxillae of G. mirabilis , Gillichthys seta , and the out‐group species Eucyclogobius newberryi was studied wi...

On September 11, 2022, two megamouth sharks ( Megachasma pelagios ), estimated at 3.7–4.6 m TL, were observed swimming together near the surface about 39 km off the coast of San Diego, CA, USA. Megamouth sharks are rarely observed pelagic sharks, and the film from this encounter provided new insight into the social behavior of this species. We attempt to put the behavior of these two individuals into the context of past sighti...

Geographically, widespread Neotropical fish lineages offer opportunities to reconstruct historical biogeography patterns and infer processes leading to modern ichthyological diversity and distribution. The characiform family Prochilodontidae is well suited for such reconstruction because their migrations limit population substructure within river systems. Therefore, their biogeographic history should match closely the history...

We report the largest specimen from the stromateoid family Nomeidae. The specimen, measuring 1283 mm total length unpreserved, was caught on hook and line from shore in Port Hueneme, California, USA in June 2019. Despite scavenging damage, the specimen was identified as a longfin cigarfish, Cubiceps paradoxus, using morphological characters and molecular techniques. This is the third record of C. paradoxus from California. We...