Question

Over 100 different species of anglerfish live at depths in the ocean where little light penetrates the waters. The female deep sea anglerfish, exhibits a spiny dorsal fin protruding above her large mouth, like a fishing pole (remember Finding Nemo?!). The tip of the “fishing pole” glows with light emitted by symbiotic photobacteria; the light attracts fish that end up entrapped by the enormous jaws of the deep sea anglerfish. In addition to prey, the species-specific bioluminescence attracts the male anglerfish. Whereas the deep sea anglerfish female is large with an expandable stomach (she can consume a prey twice her size), the male deep sea anglerfish is small, roughly 1/60 the her length, and does not feed well on his own; consequently, a large percentage of male anglerfish die “virgins” under the limited resource conditions of the deep. His well-developed eyes and nostril help him find his mate in the inky darkness amongst other female anglerfish species. Upon locating a female, the anglerfish male bites her side, releasing an enzyme that fuses his mouth to her body permanently. His eyes and fins atrophy, and his tissues and circulatory system join with hers; he essentially becomes a “sexual parasite,” unable to free himself, but fertilizing the eggs produced by the female. In some anglerfish species up to eight males can be attached to a single female

Use the paragraph above to evaluate each of the following statements as being either True or False, and explain why.

a. Speciation in deep sea anglerfish likely occurred due to behavioral isolation.

b. Since reproduction depends on blind, finless and parasitic males, deep sea anglerfish species may be on the evolutionary path to becoming blind and finless lamprey-like invertebrates in the future.

-I think this is false because the transition in the male anglerfish is similar to metamorphosis, and it is not likely that the anglerfish will convert from a vertebrate to an invertebrate.   

c. Symbiotic bacteria generate bioluminescence in the lateral line of the female, but not the male, anglerfish.

-I think this is false because only the tip of the "fishing pole" is said to be emitting light, but I am not sure about the lateral line (which is used to detect pressures and vibrations in water).

Answer 1

Ans)a)true

Behavioural isolation involves visual stimuli , smell , particular auditory stimulus like specific songs , chemical stimuli such as specific phremones .these signals are specific to each species which act as behavioural password of male and female mating.

Here in this example male anglerfish identified it's species female by visual stimuli and smell due to well developed eyes and nostril respectively so this statement is true which says speciation in deep sea anglerfish likely occur due to behavioural isolation.

Ansb)this statement is false because male anglerfish have well developed eyes which are used for identifying its own species female anglerfish

Ans-C)false. As bioluminescence occur at the tip of fishing pole of female anglerfish not along lateral line .