Lophodolos

Lophodolos Lloyd, 1909a:167 (type species Lophodolos indicus Lloyd, 1909a, by monotypy).

Lophodolus Regan, 1925c:563 (emended spelling of Lophodolos, followed by numerous subsequent authors, taking the same type species).

Oneirodes Murray and Hjort, 1912:104, fig. 90 (in part; erroneous designation; type species Oneirodes eschrichtii Lütken, 1871, by monotypy).

Lophodulus Bussing, 1965:223 (emended spelling of Lophodolos, taking the same type species).

Data for Lophodolos on the Catalog of Fishes.

Metamorphosed females of the genus Lophodolos are distinguished from those of all other genera of the family by having the following character states: The dorsal profile of the frontal bones is concave. Ventromedial extensions of the frontals are absent. The posterior end of the frontal makes broad contact with the respective sphenotic and prootic (the pterosphenoid is absent), and extends ventrally to meet the ascending process of the parasphenoid. The sphenotic spines are extraordinarily well developed and curved posteriorly. The pterygiophore of the illicium emerges from between or somewhat behind the sphenotic spines. The symphysial spine of lower jaw is extremely well developed. The medial ends of the second and third hypobranchials approach each other on the midline (see Pietsch, 1974a:25).

Metamorphosed females of Lophodolos are further unique in having the following combination of character states: The ethmoid cartilage and vomer are wide, wider than the distance between the anterolateral tips of the lateral ethmoids and frontals. Vomerine teeth are absent. The nasal foramina are extremely large and nearly circular in shape. The frontals are short, lying posterior to the ethmoid region. The anterior end of the illicial trough is wider and shallower than its posterior end. The symphysial cartilage of the upper jaw is longer than wide. The hyomandibular has a double head. The quadrate spine is extremely well developed, much longer than the articular spine. The posterior margin of the opercle is deeply notched. The subopercle is narrow and elongate, its dorsal end slender and tapering to a blunt point (the posterior margin without indentation), its ventral end narrow and oblong (a small anterior projection is present in some juvenile females). The first and second pharyngobranchials are absent. The caudal-fin rays are without internal pigmentation. The illicium is considerably longer than the length of the esca bulb. The pterygiophore of the illicium is cylindrical throughout its length, the anterior end exposed, the posterior end concealed beneath skin. There are 5–8 dorsal-fin rays, the first or anterior-most ray reduced to a small stub. There are 5–6 (rarely 4 or 7) anal-fin rays (Table 0). The pectoral-fin lobe is short and broad, shorter than the longest rays of the pectoral fin. There are 17–20 (rarely 21) pectoral-fin rays. The coracoid is without a posteroventral process. The pelvic bones are simple, but expanded distally. The skin is naked, without dermal spinules. The darkly pigmented skin of the caudal peduncle extends well past the base of the caudal fin.

The larvae of Lophodolos are unique in having the following combination of character states: The body is rather short, its depth about 60% SL. A dark V-shaped patch of pigment is present on the gill-cover (or sometimes two crescent-shaped patches of pigment meeting at the base of the lower branchiostegals, an anterior patch along the posterior margin of the opercular region, and a posterior patch along the edge of the gill cover). The dorsal pigment extends posteriorly slightly beyond the anterior margin of the dorsal fin. Peduncular pigment is absent. The ventral part of the peritoneum is unpigmented.

Metamorphosed females of the genus Lophodolos are distinguished from those of all other genera of the family by having the following character states: The dorsal profile of the frontal bones is concave. Ventromedial extensions of the frontals are absent. The posterior end of the frontal makes broad contact with the respective sphenotic and prootic (the pterosphenoid is absent), and extends ventrally to meet the ascending process of the parasphenoid. The sphenotic spines are extraordinarily well developed and curved posteriorly. The pterygiophore of the illicium emerges from between or somewhat behind the sphenotic spines. The symphysial spine of lower jaw is extremely well developed. The medial ends of the second and third hypobranchials approach each other on the midline.

Metamorphosed females of Lophodolos are further unique in having the following combination of character states: The ethmoid cartilage and vomer are wide, wider than the distance between the anterolateral tips of the lateral ethmoids and frontals. Vomerine teeth are absent. The nasal foramina are extremely large and nearly circular in shape. The frontals are short, lying posterior to the ethmoid region. The anterior end of the illicial trough is wider and shallower than its posterior end. The symphysial cartilage of the upper jaw is longer than wide. The hyomandibular has a double head. The quadrate spine is extremely well developed, much longer than the articular spine. The posterior margin of the opercle is deeply notched. The subopercle is narrow and elongate, its dorsal end slender and tapering to a blunt point (the posterior margin without indentation), its ventral end narrow and oblong (a small anterior projection is present in some juvenile females). The first and second pharyngobranchials are absent. The caudal-fin rays are without internal pigmentation. The illicium is considerably longer than the length of the esca bulb. The pterygiophore of the illicium is cylindrical throughout its length, the anterior end exposed, the posterior end concealed beneath skin. There are 5–8 dorsal-fin rays, the first or anterior-most ray reduced to a small stub. There are 5–6 (rarely 4 or 7) anal-fin rays (Table 0). The pectoral-fin lobe is short and broad, shorter than the longest rays of the pectoral fin. There are 17–20 (rarely 21) pectoral-fin rays. The coracoid is without a posteroventral process. The pelvic bones are simple, but expanded distally. The skin is naked, without dermal spinules. The darkly pigmented skin of the caudal peduncle extends well past the base of the caudal fin.

The larvae of Lophodolos are unique in having the following combination of character states: The body is rather short, its depth about 60% SL. A dark V-shaped patch of pigment is present on the gill-cover (or sometimes two crescent-shaped patches of pigment meeting at the base of the lower branchiostegals, an anterior patch along the posterior margin of the opercular region, and a posterior patch along the edge of the gill cover). The dorsal pigment extends posteriorly slightly beyond the anterior margin of the dorsal fin. Peduncular pigment is absent. The ventral part of the peritoneum is unpigmented.

Larvae of specis of Lophodolos are probably like those of all ceratioid anglerfish in that they are epipelagic and planktonic and ostensibly carried great distances by oceanic currents.

Species of the genus Lophodolos are known from all major ocean basins in tropical, subtropical, and temperate waters.

Species of Lophodolos inhabit the deep meso- and bathypelagic realms of the open ocean.

Pietsch TW. 2009. Oceanic Anglerfishes: Extraordinary Diversity in the Deep Sea. Berkley: University of California Press. 638 p.

The body is relatively long, slender, not globular. The snout is short and the mouth large, its cleft extending past the eye. The jaws are equal anteriorly. The angular bone terminates as a well-developed spine. The illicium length is highly variable, 11.1–138.0% SL, becoming longer proportionately with growth. The esca bears a pair of unpigmented, bilaterally placed appendages arising from the distal surface.

The teeth are slender, straight, all depressible, and weakly set (easily damaged or lost), arranged in overlapping sets as described for other oneirodids. The teeth in the lower jaw are larger and more numerous than those in the upper jaw. There are 200–280 teeth in the lower jaw. The third pharyngobranchial is well developed, bearing numerous teeth. Epibranchial and ceratobranchial teeth are absent.

The color in preservation is dark brown to black over the entire external surface of the body, except for the bulb and appendages of the esca (escal appendages and the unpigmented distal portion of the escal bulb appear “silvery white” in fresh specimens of L. acanthognathus). The oral cavity and guts, except for the outer surface of stomach wall, are unpigmented.

Species of Lophodolos are probably like many oneirodid taxa in that they never become parasitic. Spawning and fertilization may take place during a temporary sexual attachment that does not involve fusion of male and female tissues.

Metamorphosed females of both recognized species attain maximum lengths of approximately 80 mm SL.

As with nearly all species of deep-sea anglerfishes, those of Lophodolus lure prey to the mouth with bioluminescence emitted from the esca. Unlike most deep-sea fishes that produce bioluminescence, light produced by ceratioid anglerfishes is not endogenous, but rather the product of a bacterial community in the esca.

Lophodolos is a genus of dreamers.