Dolphins are a kind of whale.
This kind of problem often occurs.
I'm not good with that type of person.
This island has many endemic species.
In logic, 'species' refers to a subordinate concept relative to a genus.
This kind of problem is common.
A new species of fish was discovered in the deep sea.
Many species are at risk of extinction.
類 refers to a broader grouping based on shared traits (as in 人類 or 書類), whereas 種 points to a specific kind within such a classification.
種 is the precise taxonomic term for species, while 種族 is looser and can span species, genus, or family.
種 is the bare, technical term for 'species' or 'kind', whereas 一種 specifically singles out one such kind or species.
種 read as しゅ means 'kind/species' in formal or scientific contexts, while the same kanji read as たね means 'seed' or 'source' in everyday speech.
種 is the taxonomic rank of 'species', one level below 属 (genus), and learners often confuse which rank each word refers to.
kind; type; variety; category · counter for kinds, species, etc.
various kinds; all sorts; every kind
model (of machine, device) · model of aircraft; type of aircraft
race; ethnicity · type of person; breed
a kind; a sort; a variety; a species · a sort of; of sorts; something of a · sort of; somewhat
race; tribe; ethnic group · species; genus; family; taxonomic group · stellar population
product type; sort; variety of goods · taxonomic form · breed; variety; cultivar; kind
car model; vehicle model · vehicle type; vehicle classification
The kanji 種 originally depicts a heavy ear of grain and relates to seeds and planting. The reading しゅ is the on'yomi, used in many compounds. The exact historical derivation of the abstract 'kind' sense is uncertain, but it likely extended from the concrete 'seed' meaning.
inoculation; vaccination
seed; pit
classification; category; type
item; event; category
type of industry; business category
type of occupation; job category
new species; new variety
same kind; same type; same species
many kinds; many types; a wide variety
different kind; heterogeneous; heterologous
hybrid; crossbreed; mongrel
various; a variety of; all kinds of; diverse
three kinds; three varieties
sowing; seeding; planting
nuclide
different kind; another type; distinct species
variant; variation; variety · variety (taxonomy)
seed stock; foundation seed · original strain; pure breed; ancestor
seeds and seedlings · eggs and hatchlings; eggs and fry
breeding; selective breeding
mixed-breed dog; mongrel
sterilization; castration