This is official site of Black Water Dive® produced by photographer Ryo Minemizu. Black Water Dive® is a kind of night diving. We are setting up underwater lights of high-color rendering on the sea bottom of night that while considering tides, times, places. The creature which appears is mainly juveniles and larvae. All is fascinating, and it's not to be seen at daytime or regular night diving. It will be your first experience. This site will introduce the state of the event and the creatures seen and also future of BWD schedules. *"BWD"stands for Black Water Dive®.*Black Water Dive® is a registered trademark of Ryo Minemizu.

2017年1月12日木曜日

Record of Cardiapoda richardi from Kume Island


Cardiapoda known only two species from worldwide.
  • Cardiapoda richardi Vayssiere, 1903
  • Cardiapoda placenta  (Lesson, 1830)

Cardiapoda richardi

C. richardi is smaller species than C. placenta.; the tail is long like a filamentous; gill handle is shorter than C. placenta. ; gill number is eight; shell is not characterized at old literature but, actually they has a very thin shell. Retractable brown, membranous structure on the mid ventral surface of the tail. Lens of eye rests in a surrounded in a U-shaped retina. Japanese name is "Muchio-Zoukurage". "Muchio" mean tail shapes filamentous. "Zou" mean an elephant. "Kurage" mean a jellyfish.

About this individual

These pictures all took at Kume-Island Okinawa Japan. Size: about 35mm. This individual is female. Because egg strings is releasing from near the gill and Cardiapoda is known that fin sucker present only in males. Body is covered with many reddish pigment. There was a behavior to round the body. This is considered to be for defense. Brown membrane appeared only at that time. In normal posture the brown membrane is stored in the ventral surface of tail.

Cardiapoda richardi ムチオゾウクラゲ
Egg strings is releasing from near the gill

Cardiapoda richardi ムチオゾウクラゲ
Gill number is eight they has a very thin shell

Cardiapoda richardi ムチオゾウクラゲ
Lens of eye rests in a surrounded in a U-shaped retina.

Cardiapoda richardi ムチオゾウクラゲ
Retractable brown, membranous structure on the mid ventral surface of the tail.

Cardiapoda richardi ムチオゾウクラゲ
normal posture, brown membrane is stored in the ventral surface of tail.

<<References>>

Cardiapoda richardi - Tree of Life Web Project 

Chihara, M. & Murano, M. eds. ,1997 An Illustrated Guide to Marine Plankton in Japan.  Description: xxxvi, 1574pp, Tokai University Press, Tokyo Japan. (in Japanese)

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

2016年11月18日金曜日

Phylliroe bucephala is eating Rhizophysa eysenhardtii or R. filiformis

Phylliroe bucephala is eating Rhizophysa eysenhardtii Peron & Lesueur, 1807 or R. filiformis (Forskål, 1775)
P. bucephala is not so rare planktonic nudibranch. It's found at tropical and subtropical sea throughout the world. Especially, It's found many at the current-rip.

The body is thin and flat. The shape looks like a flounder fish. It has ability to bioluminescence.

Rhizophysa is kind of Siphonophorae jellyfish. They are known stocking strong poison to cnidocyte.

Phylliroe bucephala is eating Bathyphysa conifera or R. filiformis
Phylliroe bucephala is eating Bathyphysa conifera or R. filiformis


Location: Kume-Island Okinawa Japan
Time & Date: 20:30, 05, Nov, 2016
Depth: 5m, Sea Temp: 25℃
Specimen Size: 40mm


*Phylliroe bucephala Lamarck, 1816
=Phylliroe bucephalum Peron & Lesueur, 1810

Japanese name"konoha-umiushi"
="konoha" mean leaf.
="umiushi" mean nudibranchs.


<<References>>

WoRMS - World Register of Marine Species - Phylliroe bucephala Lamarck, 1816

The Sea Slug Forum - Phylliroe bucephalum

2016年9月29日木曜日

Larva of Malacanthus brevirostris Guichenot, 1848

This larva is Malacanthus brevirostris Guichenot, 1848. Taken at Black Water Dive® in Kume island Okinawa Japan.
Total length is about 55mm, relatively large larva. Snout is short protrusion. Frequently to treading water. 

Color: Red horizontal stripes pattern on body. Caudal fin has yellow-green dye, the edge has been framed in white and that outside is transparent. The rim and the base of the dorsal and ventral fins has red and yellow-green spots.

Larva of Malacanthus brevirostris Guichenot, 1848  TL:55mm

REFERENCES:
Nakabo, T. (ed.), 2013. Fishes of Japan with pictorial keys to the species, third edition. Tokai University Press, Kanagawa, Pp, 2428. (3-Volume Set)  (in Japanese).

Okiyama M. (ed), 2014. An Atlas of Early Stage Fishes in Japan Second Edition Tokai University Press, Japan. :Pp,1912. (in Japanese).

2016年8月25日木曜日

Larva of Zanclus cornutus (Linnaeus, 1758) - (family:Zanclidae)

This is larva of Zanclus cornutus (Linnaeus, 1758).
Total length about 50mm. I still have never encountered any more small size. They usually appear near the surface of water. The body is semi-transparent, it has appeared faintly black pattern. 3rd spine of dorsal fin is extended. Perceptible bumps of located above adult eye does not exist.

Larva of Zanclus cornutus
Larva of Zanclus cornutus (Linnaeus, 1758) TL:50mm
Larva of Zanclus cornutus
Larva of Zanclus cornutus (Linnaeus, 1758) TL:50mm

REFERENCES:
Nakabo, T. (ed.), 2013. Fishes of Japan with pictorial keys to the species, third edition. Tokai University Press, Kanagawa, Pp, 2428. (3-Volume Set)  (in Japanese).

Okiyama M. (ed), 2014. An Atlas of Early Stage Fishes in Japan Second Edition Tokai University Press, Japan. :Pp,1912. (in Japanese).

2016年8月24日水曜日

Brief report to Larva of Pseudochromis sp. (Perciformes, Pseudochromidae)

Somehow, larva of the Pseudochromidae has been no report so far at Japan. Pseudochromidae has been missing also at *Okiyama, 2014.

This photo was shooting at Iriomote Island of Okinawa to early June 2016.
TL; about 25mm. Depth about 3m.
Meristic Characters - D Ⅲ, 22; A Ⅲ 13; P1 17(this photo)

Pigment - This larva has orange pigment, it's dispersed throughout over the head and each scale, base of dorsal and anus fin, caudal fin base.

Study - Maybe, I'm thinking either species of Genus Pseudochromis from the Meristic character. Genus Pseudochromis are known six species of the following in sea of Japan. Above all, it seems to be one of the following two.
Pseudochromis tapeinosoma Bleeker, 1853 - (Japanese name : Katsuiro-nise suzume)
D Ⅲ, 21-23; A Ⅲ 12-14; P1 17-19; LLp 20-27+4-11; Pred.S 10-15. 
Pseudochromis cyanotaenia Bleeker, 1857 - (Japanese name : Ryukyu-nise suzume)
D Ⅲ, 21-23; A Ⅲ 12-14; P1 16-20; LLp 23-31+6-11; Pred.S 11-19.

According to the Jeffrey M. Leis & Brooke M. Carson-Ewart(ed.), 2004. Other, following species has similar Meristic characters in Pseudochromidae. but, both those are not been reported from Japan.
genus Assiculus
   Assiculus punctatus Richardson, 1846
genus Cypho
   Cypho purpurascens  (De Vis, 1884)
   Cypho zaps Gill, 2004

REFERENCES:
Jeffrey M. Leis & Brooke M. Carson-Ewart(ed.), 2004. The larvae of Indo-Pacific coastal fishes : an identification guide to marine fish larvae. Brill Academic Publication, London. Pp,850.  (second Revised).

Nakabo, T. (ed.), 2013. Fishes of Japan with pictorial keys to the species, third edition. Tokai University Press, Kanagawa, Pp, 2428. (3-Volume Set)  (in Japanese).

Okiyama M. (ed), 2014. An Atlas of Early Stage Fishes in Japan Second Edition Tokai University Press, Japan. :Pp,1912. (in Japanese).

FAMILY Details for Pseudochromidae - Dottybacks - FishBase
http://www.fishbase.org/summary/FamilySummary.php?ID=291