Animal Diversity Snail Paper

Question 1

The study found that injections of … from a gland associated with the snail “… …” more than doubled … relative to injections of ….

Answer 1

mucus, love darts, paternity, saline

Question 2

These results support the hypothesis that the dart transfers a substance capable of … the …-… organs.

Answer 2

reconfiguring, spermatophore-receiving

Question 3

Since the study also found evidence of early-male sperm …, we conclude that snails can optimise their reproductive success by mating with … and shooting their darts …

Answer 3

precedence, virgins, accurately

Question 4

In animal species that mate promiscuously, store sperm and fertilise internally, the sperm from two or more donors usually … for access to ova

Answer 4

compete

Question 5

all the prerequisites for sperm competition are present in the mating systems of … …

Answer 5

gastropod molluscs

Question 6

Sperm precedence refers to the reproductive advantage enjoyed by a sperm donor solely by virtue of its mating…

Answer 6

either before or after its competitor

Question 7

Dart shooting occurs in only about … families of pulmonate gastropods, from a total of about 60

Answer 7

8

Question 8

What species does this study look at?

Answer 8

brown garden snail (Cantareus aspersus)

Question 9

These snails are …, and both members of a mating pair function simultaneously as both … and … in all encounters

Answer 9

hermaphrodites, males, females

Question 10

Towards the end of courtship, each animal attempts to strike the other with a sharp and … dart. The behaviour is rapid and …. In about … of all shootings, the dart either … its intended target altogether or it strikes only a glancing blow, after which it falls to the ground.

Answer 10

calcareous, forceful, 50%, misses

Question 11

Importantly, the outcomes of the dart shots affect neither the … that the courtship will culminate in copulation nor the … of the ensuing sperm donation. Instead, previous work has shown that successful dart shooting more than … the number of donated sperm that are … by the recipient, and it significantly increases relative … when a successful dart shooter competes with an unsuccessful shooter

Answer 11

probability, size, doubles, stored, paternity

Question 12

Massive sperm digestion occurs in the female … of C.aspersus. On average, about 99.98% of transferred sperm are … in the bursa copulatrix before they reach the spermathecal sacs.

Answer 12

tract, digested

Question 13

Experiments performed in vitro found that the dart’s mucus contracts … muscles at the critical junction of the bursa tract and the bursa tract diverticulum.

Answer 13

radial

Question 14

Final sample of … triads, of which … had mucus injected during the first mating and … had saline injected in the first mating

Answer 14

38, 19, 19

Question 15

An interpretable sequence length was obtained at … of the probed microsatellite loci, with observed … in the range 0.69–0.89

Answer 15

85%, heterozygosities

Question 16

The fathers that donated sperm in association with … injections sired 38.9±5.2% of the offspring, whereas those that donated sperm in association with … injections sired only 16.9±3.5% of the offspring. The remaining offspring (44.2±5.5%) were sired by snails that mated with the mother prior to their collection for the study

Answer 16

mucus, saline

Question 17

Applications of dart gland mucus caused … in the snail’s spermatophore-receiving organs. These contractions reconfigured the organs in such a manner as to allow allosperm to escape … … and precede to the spermathecal storage sacs.

Answer 17

contractions, enzymatic digestion

Question 18

The bioactive substance in the dart gland mucus is likely to be a … since these are common neural and hormonal messengers in gastropod molluscs, and are present in the mucus gland secretion.

Answer 18

peptide

Question 19

Substances such as the dart gland mucus that are transferred directly into the body of a conspecific, and induce a direct physiological response, are known as …

Answer 19

allohormones

Question 20

Theory suggests that the need to increase paternity may force …, more so than species with separate sexes, to accept and develop … mating mechanisms

Answer 20

hermaphrodites, intrusive

Question 21

The study concludes that snails have two ways in which to optimise their reproductive success: by shooting darts … and by mating with …. It is unknown, however, whether snails are able to either control the … of their dart shots or identify … partners.

Answer 21

accurately, virgins, accuracy, virgin