Non-game fishes receive little attention and of these, the deep sea anglerfishes (Families Oneirodidae, Melanocetidae and Ceratiidae), are among the poorest known. Deep sea anglers live at extreme depths and few people study them.
Alive they are quite elegant with black-brown skin, flowing fins and globular bodies. But when hauled to the ocean surface and preserved in museum collections they tend to resemble shrivelled hockey pucks – with teeth. Most of what we know about these fishes is based on the females. Males are minute but have enlarged olfactory chambers. Males have one goal – to find and latch onto a female. Once attached, males draw nutrition from the female’s bloodstream. Sometimes more than one male attaches to a female, and they are in place ready to mate whenever a female is ready to release eggs. Some have said this relationship is parasitic, and while males do derive nourishment from the female, they fertilize a female’s eggs. In contrast, a parasitic relationships is one-sided. Perhaps the only time the relationship is parasitic is when a male attaches to a female of a different species – he draws nourishment, but provides no genetic contribution.
Because these fishes rarely reach the surface in good shape (trawl nets are not forgiving to soft-skinned fishes), many deep sea anglers are difficult to identify. Identification often is based on the structure and shape of tip of the lure – a structure called the esca – which sits at the tip of the first ray of the dorsal fin. If that delicate structure is lost, identification can be difficult without DNA barcoding. With DNA barcoding, we can identify species based on unique genetic sequences taken from tissue samples. One of the fishes photographed in this article, Oneirodes thompsoni, had been sampled for DNA barcoding to get a representative sequence for this species. The white tag with a code number is attached to the fish so that the fish and its genetic sequences can be matched later.
Until the paper by Weil et al. 2015, only three species, had officially been recorded from BC waters. Specimens of the large Krøyer’s deep sea angler fish (Ceratias holboelli) had been preserved, but no one had detailed where the species had been found. Several other dreamerfish had been misidentified in museum collections. The review of species known to exist here was prompted by the identification of a specimen of Melanocetus johnsonii in the RBCM collection, and the discovery of Oneirodes acanthias and Cryptopsaras couesii in 2006. The other species deemed new to BC, or representing significant range extensions, were discovered during the preparation of the paper by Weil et al. and his review of the RBCM collection.
Below is the list of anglerfish species known to exist in British Columbia (as of March 2020):
Oneirodes thompsoni, RBCM 010-00196-009, 10.9 cm Standard Length (above); and O. bulbosus, RBCM 004-00005-001, 8.8 cm Standard Length (below), are the most commonly caught dreamers along the entire BC coast. Photo by G. Hanke.
Oneirodes eschrichtii, RBCM 998-00323-002, 8.3 cm Standard Length, represents the first of its species in BC and a northward range extension of 1700 km in the eastern Pacific Ocean. Photo by G. Hanke.
Oneirodes acanthias, RBCM 010-00197-004, 10.5 cm Standard Length, represents the first specimen from BC, and a range extension of 600 km north of the species previously known range off Oregon. Photo by G. Hanke.
Chaenophryne melanorhabdus, RBCM 999-00107-002, 8.9 cm Standard Length, is another commonly caught dreamer, but we have no records north of Vancouver Island. Photo by G. Hanke.
Chaenophryne longiceps, RBCM 998-00344-001, 9.8 cm Standard Length, is one of three specimens now known from BC, roughly 600 km north of the species previously known range off Oregon. Photo by G. Hanke.
Melanocetus johnsonii, RBCM 01400308-001, 9.8 cm Standard Length, is the only specimen known from BC waters and is the first record north of Oregon on this side of the Pacific. Photo by G. Hanke.
Ceratias holboelli, RBCM 999-00081-001, 42.0 cm Standard Length, is our largest deep sea anglerfish, distinctive with its thick elongate fin rays and cover of large thorny denticles. Photo by G. Hanke.
Cryptopsarus couesii, RBCM 014-00309-001, 14.2 cm Standard Length, was caught as bycatch from the commercial fishery and since it was so strange, was kept for identification. It represents the northern most record for the species in the eastern North Pacific Ocean and a first for BC. Photo by G. Hanke.