What is the scientific study of fishes called?

Which one of the following species correctly matches its two characteristics and phylum/class?

Species	Two Characteristics	Phylum/Class
$A$. Ascaris	$i$. Body segmented,$ii$. Males and females distinct	Annelida
$B$. Salamandra	$i$. Tympanum represents ear,$ii$. External fertilization	Amphibia
$C$. Pteropus	$i$. Skin possesses hair,$ii$. Oviparous	Mammalia
$D$. Obelia	$i$. Cnidoblasts,$ii$. Organ-level organization	Coelenterata

Which pair of animal groups contains the respiratory pigment $Hemocyanin$?

Which one of the following groups of three animals is correctly matched with their one characteristic morphological feature?

Statement $X$: All chordates are not vertebrates.
Reason $Y$: $Balanoglossus$ is not a vertebrate.

Select the incorrect statements from the following:
$A$. Digestive system in Platyhelminthes is incomplete.
$B$. Bilateral symmetry is a characteristic feature of adult Echinoderms.
$C$. Pseudocoelom is possessed by Aschelminthes.
$D$. Notochord is persistent throughout life in the class Chondrichthyes.
$E$. Members of class Reptilia maintain a constant body temperature.