Here there be monsters

Abstract

Ancient mariners and early cartographers were right—there are monsters in the ocean depths, with gaping mouths, scimitar teeth and glowing appendages. These aliens have everything a science fiction movie could dream of: luminescent lures, outrageous morphology, bizarre sex habits. Fortunately, most of them are less than 20 cm long. These are the Ceratioidei, deep sea anglerfishes that are the subject of Ted Pietsch’s life’s work and a remarkable new volume, Oceanic Anglerfishes: Extraordinary Diversity in the Deep Sea. Part coffee table book, part technical reference, this beautifully illustrated book describes each species in detail, some from single known specimens. The deep sea anglerfishes are, undoubtedly, one of the most fascinating and highly derived vertebrate groups on the planet. They live in a cold, dark, inhospitable world where extreme conditions have promoted extreme morphological, behavioral, and physiological adaptations (Koslow 2006). Live observations of deep sea anglers are rare; most are described from mangled specimens trawled or dredged from hundreds or even thousands of meters below the ocean surface. They have fantastic names, like the “mischievous dreamers” (Puck pinnata) and “whipnosed sea devils” (Gigantactis spp, one of few in the suborder that are relatively large bodied at up to 40 cm). These fish make their living in a food-poor environment by use of a lure to attract prey—a stalked appendage, called the illicium, tipped with a bioluminescent bulb, the esca (Garman 1899). Escal appendages are highly diverse in size and shape, from single bulbs to filamentous branches, and most can wave to attract prey. The esca are filled with bioluminescent bacteria that are part of a symbiotic relationship that may be species-specific (Haygood and Distal 1993). Pietsch describes and illustrates the esca of all known deep sea anglerfish in detail, expounding on the diversity exhibited in the suborder as an evolutionary model for adaptation. Deep sea anglers have other luminescent structures and remarkable jaw adaptations for engulfing large prey, including members of one family (Thaumatichthyidae, the “snaggle toothed sea devils” and “wonderfishes”) that use their entire face as a net trap, complete with a glowing lure hanging from the roof of their mouths. Anglerfish bodies are generally soft and globular, with few features that can be used for diagnostic Environ Biol Fish (2010) 88:301–304 DOI 10.1007/s10641-010-9637-6