Gonatus, the most speciose genus in the family, has its highest diversity in the high North Pacific. These squids reach a maximum length of 39 cm ML.

Diagnosis

A gonatid ...

• with one or more hooks in median line on tentacular club.

1. Arms
1. Hooks in two medial series on arms I-III.
   
   
2. Tentacles
1. Tentacles present in subadults.
2. Tentacular club with one or more hooks in median line; one greatly enlarged.
3. Proximal locking-apparatus of club with suckers and knobs medial to 4-6 large ridges and grooves, and usually several smaller ones.
   

   Figure. Oral view of tentacular club of G. californiensis, 315 mm GL, immature female, preserved. Photograph of preserved club by R. Young.

3. Head
1. Radula with 5 teeth in transverse row.
   
   
4. Mantle
1. Mantle tissue muscular or flabby depending on species.
   
   
5. Fins
1. Fins sagittate, drawn out posteriorly into a short tail.
   
   
6. Photophores
1. Ocular photophores present only in G. pyros.

Comments

Many of the species characteristics are found on the tentacles. The tentacles are complex and for descriptive purposes the club and stalk are divided into various zones, regions and series as follows:

The following table compares some characteristics of subadult species of Gonatus. The most useful character states are indicated in bold-red. The table doesn't separate all species.

Species / Character	Habitat	Ocular light organs	Proximal club hooks	Distal club hook	Medial suckers of tentacular stalk	Suckers on club	Club suckers of dorsal- and ventral marginal zones merge proximally.	Arm II< III length	Club length
G. antarcticus	Antarctic waters	No	Yes	Yes	120-140	250-315	No	40-50% ML	16-17% ML
G. berryi	North Pacific	No	Yes	Yes	0-2	159-181	No	60-70% GL	30-37% GL
G. californiensis	North Pacific	No	Yes	Yes	40-80	215-270	No	46-53% GL	17-24% GL
G. fabricii	North Atlantic	No	Yes	Yes	38-109	155-229	No	53-59% GL	12-20% GL
G. madokai	North Pacific	No	Yes	Yes	Many	?	Yes	90% ML	20% ML
G. middendorffi	North Pacific	No	No	Yes	Few	?	No	50% ML	10% ML
G. onyx	North Pacific	No	No	No	0-27	160-200	No	48-54% GL	20-25% GL
G. oregonensis	North Pacific	No	Yes	Yes	70	295-370	No	59-63% ML	21-30% ML
G. pyros	North Pacific	Yes	Yes	Yes	50-125	151-184	No	60-70% GL	20-25% GL
G. steenstrupi	North Atlantic	No	Yes	Yes	75-165	190-225	No	50-70% GL	20-36% GL
G. ursabrunae*	North Pacific	No	?	?	?	?	?	42-56% ML	13-25% ML

*Known only from juveniles but with distinctive relative sucker sizes on arms and club dactylus.

Depth range based on 440 specimens in 12 taxa.
Water temperature and chemistry ranges based on 391 samples.

Environmental ranges
  Depth range (m): 5 - 3458.5
  Temperature range (°C): -0.326 - 13.742
  Nitrate (umol/L): 6.420 - 44.622
  Salinity (PPS): 33.221 - 35.328
  Oxygen (ml/l): 0.303 - 7.241
  Phosphate (umol/l): 0.575 - 3.500
  Silicate (umol/l): 3.399 - 172.531

Graphical representation

Depth range (m): 5 - 3458.5

Temperature range (°C): -0.326 - 13.742

Nitrate (umol/L): 6.420 - 44.622

Salinity (PPS): 33.221 - 35.328

Oxygen (ml/l): 0.303 - 7.241

Phosphate (umol/l): 0.575 - 3.500

Silicate (umol/l): 3.399 - 172.531
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Brooding of egg masses in G. onyx (Seibel et al., 2000) [suspected in G. fabricii (Bjorke et al., 1997)] occurs in deep water. Such brooding behavior, rare in oceanic squids, may prove to be characteristic of all members of the genus and perhaps the entire family. The long brooding period demanded by cold temperatures in deep water and its resulting slow population turnover rate, presumably is offset, in evolutionary time, by low egg mortality in the vast, dark, lowly populated bathypelagic environment (see Seibel, et al., 2000). For more information on brooding behavior, go to the G. onyx page.

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There is 1 barcode sequence available from BOLD and GenBank.   Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen.  Other sequences that do not yet meet barcode criteria may also be available.


Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1

Barcode of Life Data Systems (BOLD) Stats
                                        

Specimen Records:	103	Public Records:	25
Specimens with Sequences:	82	Public Species:	10
Specimens with Barcodes:	82	Public BINs:	8
Species:	13
Species With Barcodes:	11

Access Published & Released Data: Download FASTA File

Collection Sites: world map showing specimen collection locations for Gonatus