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Hatch MatchHook the Horizon · field intelligence

Cephalopoda, Loliginidae

Inshore squid

The class this reference has had a name for since v8, and no animal in it until now.

First checkCount the long arms. Eight arms plus two much longer tentacles is a squid; eight and nothing longer is an octopus.

A squid is eight arms, two much longer tentacles with spoon-shaped sucker-covered ends, a torpedo-shaped mantle, and a pair of fins that in the longfin run at least half the length of that mantle — which is the character the common name is built on. It moves by pumping water in through the open mantle and forcing it out through a funnel, so it goes backwards on purpose, and it changes colour and pattern while you watch by expanding and contracting pigment cells in the skin. It is also, per NOAA, probably colour blind, which is a fact worth sitting with.

For an angler the useful behaviour is vertical. Adults are on the bottom by day and disperse up into the water column at night; young squid are abundant in the upper ten metres over fifty to a hundred and fifty metres of water. North of Cape Hatteras they come inshore in spring and stay until late autumn, then move out to the shelf edge for winter — and off Massachusetts the big ones arrive first, in April and May, with the smaller ones following in summer.

Now the honest part, and it is a big one. Nothing in the consulted sources describes what a squid looks like from the surface, in the surf, or in an estuary. NOAA states plainly that the Pacific market squid is rarely found in estuaries, bays or river mouths. If you are watching bait flush in a bay and wondering whether it was squid, this record cannot help you, and it is not going to pretend it can.

The tell

What settles it, and what settles against it.

Read off this record's own diagnostic weights, heaviest first. A structure near the top of the left column does most of the work on its own; one near the bottom only leans.

Argues for Inshore squid

  • Eight arms plus two longer tentacles+8
  • Fins along a torpedo-shaped mantle+7
  • Shoots backwards in a jet, and changes colour+6
  • Moving as a school or tight bait cluster, not as a single insect+3
  • Body translucent — light passes through it, and the backbone or gut shows+2

Argues against it

  • Fish-shaped forage silhouette (minnow / shiner / fry) — not an insect-4

A structure at −4 or below is treated as a hard exclusion by the comparison tool rather than as a penalty: if you saw it, this group is ruled out and no amount of matching elsewhere brings it back. Run a comparison →

Life stages

What it looks like, stage by stage.

Nothing consulted describes a paralarva beyond its mantle length, so there is nothing reviewed to draw.
Inshore squid — Paralarvagap

Paralarva

Size in hand1.4–15 mm mantle length

What you see

  • Mantle length is the only sourced character at this stage

Where it turns up

In the plankton.

How it moves

No consulted source describes it.

Inshore squid — Juveniledrawn

Juvenilethe stage a fish meets

Size in hand15–80 mm mantle length

What you see

  • Fins already long relative to the mantle
  • At about 45 mm the pigment cells shift to the upper surface, marking the move from surface water to a life near the bottom

Where it turns up

Abundant in surface water, in the upper ten metres over fifty to a hundred and fifty metres.

How it moves

Schools. Jets backwards.

Cues this stage offers the comparison

  • Eight arms plus two longer tentacles
  • Fins along a torpedo-shaped mantle
  • Shoots backwards in a jet, and changes colour
Inshore squid — Full-growndrawn

Full-grown

Size in hand80–490 mm mantle length, most under 300 mm

What you see

  • Fins running at least half the length of the mantle
  • Eight arms plus two much longer tentacles with spoon-shaped, sucker-covered ends
  • Large eyes covered by a clear cornea
  • Typically pink or orange, mottled with brown or purple, and changing as you watch
  • A stiff internal shell — the pen — inside the mantle

Where it turns up

On the bottom by day, up into the water column at night; inshore spring through autumn, offshore along the shelf edge in winter.

How it moves

Shoots backwards in a jet by pumping water through the funnel. Schools.

Cues this stage offers the comparison

  • Eight arms plus two longer tentacles
  • Fins along a torpedo-shaped mantle
  • Shoots backwards in a jet, and changes colour
  • Moving as a school or tight bait cluster, not as a single insect

Confused with

Telling it from what it isn't.

Inshore squidMarine worms

A segmented body with flaps down the sides and no arms is a worm.

Open Marine worms →

Inshore squidShrimp (grass and penaeid)

A shrimp has a jointed shell, legs and a tail fan. A squid has none of those — it is soft the whole way through except for the pen.

Open Shrimp (grass and penaeid) →

Water and depth

Where the record puts it.

Water types documented

  • nearshore
  • inshore
  • offshore

Where in the column it mattersMid column. The band is set by the clock rather than by the season: bottom by day, up in the column at night.

Read from the record's own position notes: on the bottom by day, dispersing up into the water column at night; young squid abundant in the upper ten metres over water fifty to a hundred and fifty metres deep.

Reference windows

When this group is typically available.

Typical published ranges only. Elevation, latitude, tailwater release and a given year's weather move all of these, often by weeks. This is never a statement about today.

2 reference windows
Inshore seasonadult

Longfin squid move inshore once coastal water is at least about 48 °F, larger animals first and smaller ones through the summer. No upper band is given here because no source read gives one.

Not stated by the source

Offshore for winteradult

Sub-adults are out on the outer shelf from about November until March. Spawning cohorts occur throughout the year, so the seasonal signal here is the movement, not the spawn.

Not stated by the source

See the full seasonality view →

What eats it

Which fish the dossiers actually name.

No reviewed dossier names this group. That is an absence in the dossier layer rather than a finding about the animal — four dossiers exist and only one of them names any forage group at all.

Forage described only in class terms

What that implies for presentation

Nothing in the pattern layer is mapped to this group, so no presentation family follows from it here.

Not known

What this entry cannot tell you.

10 of them. The limits are part of what was reviewed rather than a disclaimer bolted on afterwards. An entry that hid them would be claiming more than it checked.

Written by the reviewer

  • Declared by the reviewerNo consulted source states an arm and tentacle count for the longfin squid specifically; the eight-plus-two count is sourced as a general squid character and for the Pacific market squid.
  • Declared by the reviewerAtlantic and Pacific inshore squid are separated in the literature by ocean, not by any character.
  • Declared by the reviewerNothing consulted describes squid from the surface, in the surf, or in an estuary.
  • Declared by the reviewerNo source consulted states an arm and tentacle count for the longfin squid specifically. The eight-plus-two count is sourced as a general squid character and for the Pacific market squid.
  • Declared by the reviewerAtlantic and Pacific inshore squid are separated in the consulted literature by ocean, not by any character. No source consulted gives a morphological separator.
  • Declared by the reviewerNothing in the consulted sources describes what a squid looks like from the surface, in the surf or in an estuary. NOAA states plainly that market squid are rarely found in estuaries, bays or river mouths. If you are watching bait flush in a bay, this record cannot tell you it was squid.
  • Declared by the reviewerMaximum mantle length is published as over 40 to 50 cm, as 47 cm, and as 1.6 feet. Roughly consistent, but no one figure is offered as definitive.
  • Sources disagreeSpawning windows for the Pacific market squid differ between two sources that also name different regions: April to October in central California in NOAA's account, April to November in northern California in California Sea Grant's.

Read off the record

Nobody typed these. They are fields that are empty, said out loud rather than left for you to notice from a section that simply is not there.

  • PatternsNo fly pattern in the pattern layer is mapped to this group. Whether anything imitates it is not answered here.
  • What eats itNo reviewed species dossier names this group. Some dossiers describe forage in class terms — small forage, insects, bait — and those are shown below, but a class description is not a reviewed link to this group and none is claimed.

Sources

Everything above rests on 7 published pages.

Attribution here is to the whole record, not to individual sentences — the carrier attaches a source set to a record and does not say which page carried which line. Naming one per claim would mean inventing a mapping nobody reviewed.

Carrier reviewed 2026-09-04 · next review due 2026-12-03 · oldest page behind this record read 2026-09-04

Every source in the app, filterable →

Watch the structure

The field marks, moving.

A plate shows shape. It cannot show a gill beating, a mask firing, or an animal reversing into sand — so where motion is the field mark, the entry points at motion. These are demonstrations, selected by hand and by publisher. Nothing here is a source: it changes no score, no window and no reviewed claim.

Carry it on

Take the group to the next step.

These send the class of animal and the water this record is documented in. They do not send a sighting, because this page does not have one — you have not told it what you saw.

  • Which fish in this kind of water are documented eating this class of forage, and how they behave when they are.

  • What this forage class asks of the setup — the weight it wants, and where the chain gives first.

  • Keep the group on the day's record, so a later entry can be compared against what you were looking at.

Found an error?

This entry was written and drawn away from your water. If something here is wrong, say so — the report is assembled in your browser and sent only if you send it.

Report an error in Inshore squid →

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