Grow and smaller aren’t linked or related (described further here) as they are interchanging. If a fish has grew to a certain size in adulthood, it is shrinking further than their predecessors, so they are bigger than them.

What does “GROW” mean? What do the first two reflect what we often immediately think of when we think

about growing: growth ( v. ). To undergo natural development, to increase in size and change physical growth

v. ) to become bigger or greater over a period of time; to increase

I’m the third meaning, though, that provides the key to your apparent oxymoron:

grow ( v. x). If the number of fish are gradually becoming diminished/emerging, then a headline might

say : Tasty Fish Grow Smaller/Emergence, causing the fish to become smaller over time? (or,

maybe more accurately, causing the average size

of adult fish to become smaller over time)

What you are referring to is the basic form of speech that we use informally but not correct. To me, this is a right usage. Something can shrink smaller? Also sometimes “grow smaller” can be used as an oxymoron in a poem.

As well as the common usage of grow to increase in size it can also be used to indicate a gradual or progressive change of state for example

As the night fell it began to grow colder.

Having said that using the phrase ‘grow’ smaller is probably best avoided as it is a bit ambiguous as it is not clear whether it means they actually shrink or they just grow more slowly, reach a smaller maximum size or indicating a trend in in the population as a whole over time.

Although this is often the case with headlines and often the ambiguity is deliberate in order to make a story sound more interesting or sensational than it really is.

I don’t see any conflict in it. It is too complex and confusing.

Yes, “span” means to grow and they are! But they grow less than the initial expectation.

Why do most fish grow bigger as humans get older?

What does it mean when you say “don’t believe in yourself”?

I think you can use ‘grow’, since there is an increase of’smallness’ compared to a previous state. If I grow larger, does it mean small fish turn small? From what we can tell, fish are slowing or they stop growing earlier. Nevertheless you have the act of ‘growing’ from tadpole to fish. This is what ‘grow’ refers to, it is not a general phenomenon that happens to the common fish..

So long and thanks for all the fish!