Species-specific bioluminescence facilitates speciation in the deep sea

Abstract

The vast darkness of the deep sea is an environment with few obvious genetic isolating barriers, and little is known regarding the macroevolutionary processes that have shaped present-day biodiversity in this habitat. Bioluminescence, the production and emission of light from a living organism through a chemical reaction, is thought to occur in approximately 80 % of the eukaryotic life that inhabits the deep sea (water depth greater than 200 m). In this study, we show, for the first time, that deep-sea fishes that possess species-specific bioluminescent structures (e.g., lanternfishes, dragonfishes) are diversifying into new species at a more rapid rate than deep-sea fishes that utilize bioluminescence in ways that would not promote isolation of populations (e.g., camouflage, predation). This work adds to our understanding of how life thrives and evolution shaped present-day biodiversity in the deep sea, the largest and arguably least explored habitat on earth.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-014-2406-x) contains supplementary material, which is available to authorized users.

Endohelminth parasites of some midwater and benthopelagic stomiiform fishes from the northern Gulf of Mexico

“…Individuals of both phosichthyid species tended to be longer and heavier than the sternoptychid species (Table 3). The cox1 sequence of Argyropelecus aculeatus and Maurolicus weitzmani was identical to that of the unpublished sequence of Argyropelecus aculeatus (KF929623) collected from the slope water off Cape Hatteras and the sequence of Maurolicus weitzmani (KJ190037) from the Mid-Atlantic Bight (Davis et al 2014), respectively. The cox1 sequence of Polyipnus clarus differed from that of the Polyipnus clarus sequence FJ918932 collected from the slope water of southern New England (DeVaney 2008) by a single purine transition.…”

Bioluminescent sexually selected traits as an engine for biodiversity across animal species

“…It was known that bioluminescence has evolved independently more than 40 times, with males often using it as a mating signal but with also some other possible adaptive functions including anti-predator defense and predation. Moreover, it has been reported that small marine lanternfishes and sharks that use bioluminescence in mate identification had a greater concentration of species than other deep-sea fishes that use bioluminescence for defensive purposes [2][3][4]. But no one had ever determined whether this pattern is consistent across diverse and distantly related animal groups living on sea and land.…”

Light organ anomalies in three species of myctophid fishes (Actinopterygii: Myctophiformes: Myctophidae) from the Pacific coast of Mexico

“…Different types of anomalies and abnormalities in fi shes are well documented (Dawson 1964, 1966, 1971, Dawson and Heal 1976. However, anomalies are scarcely or never reported among deep-sea fi shes, and there are very few records concerning variation in the number and position of primary photophores (Davis et al 2014, Klepadlo et al 2014. Some lanternfi shes have been found with slight variation in the diagnostic position of a single photophore (usually only one side of the body), which was not considered taxonomically signifi cant and attributable to local factors (Wisner 1976, Hulley 1986, Klepadlo et al 2014.…”

“…Recently, Davis et al (2014) showed that lanternfi shes are diversifying into new species at a more rapid rate than many other deep-sea fi shes. This was explained by their lateral body photophores that exhibit species-specifi c properties that may play a functional role in species recognition-communication, and, as a result, contribute to genetic isolation, in contrast with the species that utilize bioluminescence in ways that would not promote isolation of populations (e.g., camoufl age, predation).…”

“…Given limited identifi cation of species-specifi c properties (e.g., communication) in the anomalous light organs discussed herein (i.e., PO series and VO series; see Davis et al 2014Davis et al : p. 1145), these anomalies, as suggested by Klepadlo et al (2014), might be just an aberration, a genetic abnormality in the populations sampled, an indicator of local races (sensu Tamoykin and Trofi mov 1986) or phenotypic plasticity in photophore position and orientation in the Myctophidae (P.A. Hulley, personal communication).…”