The Firefly squid of Toyama Bay

English name: Firefly squid
Latin name: Watasenia scintillans (Berry, 1911)

Toyama Bay is famous for Firefly squid production. That mainly season is between March to May. This season is for Spawning. Distribution of Firefly squid is around Japan of Okhotsk Sea from coast of South Japan. Among them, the largest Firefly squid live in Toyama Bay, common size is ML70mm. It's much larger than those of other regions.

Firefly squid, Watasenia scintillans (Berry, 1911)

eggs drifting in underwater

Two to four large organs covered by black chromatophores on tips of arms IV.

REFERENCES
Watasenia scintillans - Tree of Life Web Project

Some jellies in early spring of Toyama bay.

In early spring of Toyama Bay, we were able to find  meny number of jellies. Among them, the comb jellyfish was seen many. Sea temperature is 10 or 11 degrees celsius.

This Cydippida sp. of size is about 20mm. it's had mature eggs.

Cydippida sp. 

This Hormiphora has a secondary tentacles of yellowish. Size is 45mm.

Hormiphora sp.

Aglantha digitale is one of Trachymedusae. In early summer from spring, It can see the coast of Hokkaido from Northeast and Hokuriku Japan. Umbrella of muscular glow to rainbow colors depending on the angle of light.

Aglantha digitale (Müller, 1776)

Beroe mitrata looks like Beroe forskalii. but, the pharynx of Beroe mitrata is characteristic by dyed red.
This individual is still young, size is only about 30mm.

Young of Beroe mitrata (Moser, 1908) 

Cyclosalpa bakeri　habittat around from 45 degrees north latitude to near 40 degrees south latitude of East Atlantic, Pacific Ocean and Indian Ocean.

Aggregate zooid of Cyclosalpa bakeri Ritter, 1905

Aggregate zooid of Cyclosalpa bakeri Ritter, 1905

Thetys vagina is biggest in solitary zooid of Salpida. This individual size is about 170mm.

Solitary zooid of Thetys vagina Tilesius, 1802

REFERENCES
Ryo Minemizu et al ,2015 A Photographic Guide to the Jellyfishes of Japan. 360pp. Heibonsha, Tokyo Japan. (in Japanese)

Unidentified Clionidae species in Toyama Bay.

We did pre Black Water Dive® at Namerikawa of Toyama Bay from 18th Mar to 20th Mar. Sea temperature was 10 degree. Visibility is not very well at that time, the results are were few. Most that we have found, it's common in the drifting plankton and nekton. However, there was a new discovery.
This is a very small Clionidae species. Size only 2mm. Cilia ring is three-stage.
So far, C, limacina limacina has not a report from Toyama Bay.
This species has also been reported from water sampling facilities of deep sea water of Toyama so far, and it has been found to be a new species.

Clionidae species

Oct/12/2017 Postscript
There seems to be some announcement today.
http://www.tokyo-np.co.jp/s/article/2017101201000867.html
http://www.sanyonews.jp/article/610835/1/
富山湾で発見されたクリオネの仲間ですが、蘭越町貝の館の山崎さんや富山大学らの共同研究により、新種記載されることになりました。

Leucopsarion petersii Hilgendorf, 1880 of Toyama Bay

TL: about 50mm
Japanese common name: Shiro-uo
English name: Ice-goby.
Latin name: Leucopsarion petersii Hilgendorf, 1880

Ice-goby famous is also in Toyama Bay. It's inhabit the coast of the shallow sea, and eat of plankton. also, gather well in front of the light at Black Water Dive^®. Adult is run-up to the lower reaches of the river in early spring for spawning. The silver color in the center of the body is the air bladder. This picture is female.

Leucopsarion petersii Hilgendorf, 1880

Larva of Blanket Octopus,Tremoctopus gracilis (Eydoux & Souleyet, 1852) Tremoctopodidae.

This larva of a Blanket Octopus was taken at Omi Island Yamaguchi Prefecture Japan.
Omi Island is located in the Sea of ​​Japan coast of Yamaguchi Prefecture.

This larva of mantle length was about 4mm.
Mantle is translucent, brachial membrane envelops head and arms.
Ciliary process are lined to Mantle.

Lateral view

Among the larvae of the arm, dorsal arms is the most developed and the other arm is quite short.
Dorsal arms has very large suckers. Sucker is gradually to bigger from the tip, and the largest sucker is fourth from the tip. Web of arms is not yet developed.

Chromatophores present on inner edge of each sucker, and absent on funnel.
Orange large iridophores are arranged around the eyes.

Dorsal view

Mantle typically triangular in shape.

Dorsal mantle scattered with chromatophores.

ventral view

Large eyes are facing the ventral.

Ventral mantle patterned with a band of yellow from red chromatophores along anterior margin.

Other Notes;

Often, adult of Tremoctopus gracilis appear to Omi Island in late summer. Genus Tremoctopus are pelagic octopus that live on the surface to 250m. And also known to feed on Pteropod Molluscs and small fishes. Larva often known that hold on Physalia tentacles in arms I and II.

REFERENCES

Sweeney, M.J., Roper, C.F.E., Mangold, K.M., Clarke, M.R., and Boletzky, S. v. 1992. 'Larval' and juvenile cephalopods: a manual for their identification. Smithsonian Contributions to Zoology - No. 513. 282pp.

Norman, M.D. 2000. Cephalopods A World Guide. Frankfurt, Germany, IKAN Publishing. 320 pp.

Jereb,P., Roper,C.F.E.,Norman,M.D.,Julian,K.F., 2014. Cephalopods of the World. An annotated and illustrated catalogue of Cephalopod species known to date Volume 3 Octopods and Vampire Squids. FAO Species Catalogue for Fishery Purposes No.4, Vol.3. 382pp.

Tremoctopus - Tree of Life Web Project

Amphitretus pelagicus Hoyle, 1885

Amphitretus pelagicus is very unique an Octopus. Body is gelatinous and translucent, it's like a jellyfish. This is pelagic species of open waters. Habitat is from near surface depths to at least 2,000 m.

This individual was found in -5m at Osezaki Shizuoka Japan on 27th November 2014.
Osezaki is a part to coast of Suruga Bay.

This individual size is about 100mm ML.

Dorsal view of Amphitretus pelagicus

Many chromatophores are on inner body, and small chromatophores are on web.

Lateral view of Amphitretus pelagicus

Eyes like a periscope, it's to the dorsal side.

Arms and web of Amphitretus pelagicus

Suckers is one row at proximally and two rows at near the tips.

Upside-down pose of Amphitretus pelagicus

Arms can enclose the head. Perhaps, it's for defense.

REFERENCES:
Amphitretus - Tree of Life Web Project

Jereb,P., Roper,C.F.E.,Norman,M.D.,Julian,K.F., 2014. Cephalopods of the World. An annotated and illustrated catalogue of Cephalopod species known to date Volume 3 Octopods and Vampire Squids. FAO Species Catalogue for Fishery Purposes No.4, Vol.3. 382pp.

伊豆大島BWD 3日目

3日目の報告です。
昨夜の秋の浜は風も収まって、前日より凪いでいてくれましたので難なくエントリーできました。ゲストも多い日でしたので一安心です。

ホシムシ類のペラゴスフェラ幼生

私は生物を探す際にINONの超挟角ライトLF800Nを使っているのですが、それにダイビングベル（通称チャリチャリ）を直接つけていて、何か珍しい生物がいたらそれを大きく振って光と音で皆さんを呼びます。昨夜も比較的大型のヒメセミエビ属のフィロソーマ幼生がライト前に現れましたので、チャリチャリ鳴らしましたが、皆さん集まるの早すぎます（笑）で、ゲストの皆さんの撮影が一巡した後に、少しだけパシャリと撮影。わしゃわしゃと周りにいる微小プランクトンを食べている様子が見られました。

ヒメセミエビ属のフィロソーマ幼生　甲幅約23㎜

小さい個体でしたが、ホタルイカモドキ属の一種も現れました。

ホタルイカモドキ属の一種　ML約15mm

タルマワシの一種のオス個体も現れました

コエビ類のゾエア幼生

ミズヒキガニのメガロパ幼生　横から

Black Water Dive　昨夜の風景

今夜はあいにく北東の風が強く吹く予報ですので、「秋の浜」は大時化になることが予想されます。ですので、急きょ場所を変更して未知数な部分もありますが、「王の浜」で開催する予定です。