Frogfish

Abstract: The “Lembeh Frogfish” or “Ocellated Frogfish,” a distinct antennariid, known for many years, especially among members of the dive community, and suggested by some to represent an undescribed species, is identified as Nudiantennarius subteres (Smith and Radcliffe). Unique in several ways—including reduced dermal spinules, the body appearing naked; illicium short, about half the length of the second dorsal-fin spine; second dorsal-fin spine unusually long and narrow, without a posterior membrane; pectoral lobe narrow, somewhat detached from the body; membranes between the rays of the paired fins deeply incised; and all pelvic-fin rays simple—the species is redescribed and figured below. Morphological and molecular analyses indicate a close relationship with the Sargassumfish, Histrio histrio.

Abstract: Eophryne barbutii gen. et sp. nov., a new frogfish from the Ypresian of Monte Bolca (Italy), is described. This taxon is the oldest member of the family Antennariidae known to date based on articulated skeletal remains. Eoph- ryne barbutii gen. et sp. nov. possesses a unique combina- tion of features that supports its recognition as a new genus of the family Antennariidae. It is characterized by the pres- ence of tiny bifurcated dermal spinules on the skin between and on the surface of the second and third dorsal-fin spines, a naked illicium, outermost caudal-fin rays simple, caudal peduncle present, 11 dorsal-fin rays, and seven anal-fin rays. Eophryne gen. nov. shows a certain degree of phenetic resem- blance to the extant genera Antennarius, Histrio and Nudian- tennarius. Palaeoecological and evolutionary implications are also discussed.

Abstract: The fin-to-limb transition is heralded as one of the most important events in vertebrate evolution. Over the last few decades our understanding of how limbs evolved has significantly increased; but, hypotheses for why limbs evolved are still rather open. Fishes that engage their fins to ‘walk' along substrate may provide some perspective. The charismatic frogfishes are often considered to have the most limb-like fins, yet we still know little about their underlying structure. Here we reconstruct the pectoral fin musculoskeletal anatomy of the scarlet frogfish to identify adaptations that support fin-assisted walking behaviours. The data are compared to three additional anglerfish species: the oval batfish, which represents an independent acquisition of fin-assisted walking; and two pelagic deep-sea swimmers, the triplewart seadevil and ghostly seadevil. Our results clearly show broad musculoskeletal differences between the pectoral fins of swimming and walking anglerfish species. The frogfish and batfish have longer and more robust fins; larger, differentiated muscles; and better developed joints, including a reverse ball-and-socket glenoid joint and mobile ‘wrist'. Further, the frogfish and batfish show finer-scale musculoskeletal differences that align with their specific locomotor ecologies. Within, we discuss the functional significance of these anatomical features in relation to walking, the recurring evolution of similar adaptations in other substrate locomoting fishes, as well as the selective pressures that may underlie the evolution of limbs.

Abstract: The present paper reports the first record of one antennarid species from the Gulf of Oman and the second record of another frogfish from the Arabian Sea coasts of Oman. The record of Antennarius coccineus is a north-eastern extension of its distribution in Omani waters. Antennarius indicus was recorded for the second time from the Arabian Sea coasts of Oman.