First cyprinodont record from The Netherlands

The fossil quarry Miste (Winterswijk, The Netherlands) is well known for its fish otoliths. A single otolith, previously determined as †Prolebias weileri Von Salis 1967 by Schwarzhans (2010) is now assigned to the fossil genus †Paralebias.

(Photo:) I am keeping the one and only small [very small!] piece of evidence proving the cyprinodont family Pantanodontidae once lived in The Netherlands, in my hand! The type specimen (the tiny, yellowish spot of hardly 1 mm in the center of the container) is kept at Naturalis Biodiversity center. (Leiden, The Netherlands).

†Paralebias sp. Miste is the most northern cyprinodont (fossil ánd extant) found in Europe thusfar. Its closest relatives are found 700 km south of Miste in the Mainz basin (Germany). The quarry is of Miocene age (estimated 15-10 Ma); as such this species is the youngest fossil species of †Paralebias. 

Together with Jean Huber I have finished a comprehensive review on Pantanodontidae. Besides the fossil genus: †Paralebias Gaudant 2013 and Pantanodon Myers 1955 (until recently the only extant genus in this family) we described two new extant genera and five new species. We suspect the diversity in extant species in this family, only found in East Africa and of which some are considered extinct, to be even greater.

All of the known fossil species are found in Europe; a new study will show the diversity in this genus certainly is greater than presently understood. 
More details in my blog "For real" (and the references below).

The map above shows the distribution and (estimated) age of all presently valid species. Artist impressions ©Eduard Meinema.

References:
Meinema, Eduard & Jean H. Huber (2023): Review of Pantanodontidae (Cyprinodontiformes) and its fossil and extant genera Pantanodon Myers, 1955 and †Paralebias Gaudant, 2013 with descriptions of two new recent genera and five new species.- Killi Data series, April 24, 2023: 21-73.
Schwarzhans, Werner (2010): The Otoliths from the Miocene of the North Sea Basin. - Publisher: Backhuys Publishers & Margraf Publishers, 352 pp. ISBN 978-3-8236-1582-8.

The secret garden (eels)

A secret garden is exciting; if you're able to find it of course. You will not find any Garden Eels in there though. These fish... yep, hard to understand, but these worm like creatures really are fish; so... these fish live in the sea. They are not that difficult to find, but rather uneasy to collect as they quickly disappear when approached. Where do they go? Into their tube like holes. Which may seem hard as some species can easily grow up to 60 cm length. But garden eels are masters in digging; they disappear, tail first, into their private space.

There are a few dozen species, each having their own color pattern. These patterns range from black blotches, or black and white zebra stripes,  to the 'Nemo-like' orange and white banded eels, known as Splendid Garden Eels (Gorgasia preclara). Last month a new species was described. Heteroconger fugax, based on a typical white blotch near its gill openings. Although its description is based on a single specimen, from Amami-oshima Island in Japan, photographic evidence proved the new species has a rather wide distribution area which includes Borneo and the Philippines. 

Imagine the ocean floor, empty and deserted. So it seems; but if you wait for a minute or two you will see the head of a fish popping up. Within seconds the ocean floor is filled with waving worms. Garden Eels, living closely together, feeding on small particles of food drifting by. One move and they're gone. Have a look at this magnificent group of garden eels at Bali, to get the feeling.

References
Koeda, K. Fujii, T & Motomura, H. (2018): A new garden eel, Heteroconger fugax (Congridae: Heterocongrinae), from the northwestern Pacific Ocean. - Zootaxa, 4418 (3): 287-295.

Original artwork available:

Prints of the artwork in this blog can be ordered at my printshop in full and in detailed version (without the white borders).

Oh Rhads... Adult coloring

The hype or craziness about coloring books for adults seems to be done these days. Too bad, as these fish would be perfect candidates for anyone willing to create their own Rainbowfish. And you know what? No matter what colors you will add to the black and white drawing; there is a high probability your own design may be found in nature. How's that? 

This blog refers to Rhadinocentrus ornatus; Australian Rainbowfish shortly referred to as Rhads. A fish that has been quite popular in the early 1900's. Easy to keep and easy to breed. Pretty little fish (hardly exceeding 7cm length) and the only species in the monotypical family Rhadinocentrus. That's right a family with only one species. One species, but incredibly variable in coloration. Not only does this species differ in coloration in between habitats; even specimens from the same locality can show differences in coloration (as can be seen in the photos of Peter Hansler, showing red and blue morphs, males, from Snapper Creek, Queensland). So, there you are. Give it a try and create your own color morph of Rhads.

Rhadinocentrus belongs to the colorful Rainbowfish. The genus has been described in 1914 by Regan as it differs from other Rainbowfish by the soft finrays. The scientific name is based on the Greek words 'rhadinos' (soft or flexible) and 'kentron' (sting). 
The color morph I painted originates from Carland Creek, Queensland.

Want to give it a try yourself? Print the coloring plate and have fun!

Buy this item:

Prints of the artwork in this blog can be ordered at my printshop in full and in detailed version (without the white borders).

References
Hansler, Peter: Rainbowrunner (website)
Regan, C. T.  (1914): Report on the freshwater fishes collected by the British Ornithologists' Union expedition and the Wollaston expedition in Dutch New Guinea. - Transactions of the Zoological Society of London Vol. 20 (pt 6, no. 1) (art. 6): 275-286, Pl. 31
Tappin, Adrian R. (2016): Rhadinocentrus ornatus - Rainbowfish (website)

These fins are made for...

Fish swim. However... You would be surprised if you knew how many species of fish are known because of their flying skills. In most cases, leaving the water is an act of fear. A way to escape predators. The most well known flying fish have elongated fins, which give them the opportunity to glide through the air. The freshwater hatchet fish for instance, Carnegiella species, are well known aquarium fish which also use the air to escape predators. Their body is shaped like a hatchet (Ah! Now you know how they got their vernacular name!) The body is used to glide along the water surface after landing. Real surf dudes these guys!

The fish I have painted today do not fly, glide or surf. But they do have long elongated fins. The Robertsi Tetra has been known by hobbyists for many years (since 1956 to be precise) before it finally got its scientific name in 2014: Hyphessobrycon jackrobertsi. A truly beautiful fish, especially when the males are showing off. Because that's what they use their fins for: dress to impress.

I just love all those colorful tiny tetras. Most of them are doing fine in small groups and easily adapt to the aquarium. In most cases even breeding them is rather easy. I have studied the species of Megalamphodus in 1988; in those days recognised as a valid family name. For the moment Megalamphodus is replaced to Hyphessobrycon. A characid family which includes more than 100 species; its status is still not definitely clarified. A friend of mine, Peter Boeters, a well known fish breeder in those days who passed away too young, had found a few mysterious fish in an aquarium shop. He could not determine the name and asked me to help him out. It took me quite a while, researching ichthyological literature, before I found their name: Megalamphodus eques. That is; I believed I was right at the time. As said the status of the rosy tetras is far from clear; today I am not so sure about my determination any more. 

Eventually my search for the unknown tetra led to my first article published in an official (Dutch) aquarium magazine. I have made a scan of the article (sorry, its all in Dutch) including two of my first drawings and photos of the presumed M. eques: 'Megalamphodus en nog wat' ('Megalamphodus and something else').

References
Eigenmann, C.H. (1915): The Cheirodontinae, a subfamily of minute characid fishes of South America. - Memoirs of the Carnegie Museum, Volume 7 (no.1): 1-99. pls. 1-17.
Weitzman, S.H. and L. Palmer (1997): A new species of Hyphessobrycon (Teleostei: Characidae) from the Neblina region of Venezuela and Brazil, with comments on the putative 'rosy tetra clade'. - Ichthyological Exploration of Freshwaters, Volume 7 (no.3): 209-242.
Zarske, Axel (2014): Zur Systematik einiger Blutsalmler oder „Rosy Tetras" (Teleostei: Ostariophysi: Characidae). - Vertebrate Zoology 64 (2): 139-167.

Original artwork available:

Prints of the artwork in this blog can be ordered at my printshop in full and in detailed version (without the white borders).

Bigger Trigger

Made a smaller Triggerfish a few weeks earlier (see my blog 'Triggered'). This week I completed a larger painting (40x120 cm / 15.75 x 47.25), made with sand and acrylics titled 'Square Leopard'. It shows the Leopard or Clown Triggerfish, Balistoides conspicillum (Bloch & Schneider, 1801), upon a nice blue background with red, coral like squares.

Original artwork available:

Prints of the artwork in this blog can be ordered at my printshop.

Flashin' Fairies

Paracheilinus is an Indo-Pacific genus of labrid fish, known as flasher or fairy wrasses. The small fish, hardly exceeding 7 cm of length, are found at depths of 10-65 metres. The genus has been described in 1955; but only since the 1970's, when ichthylogists started to use scuba equipment, these beauties became really known. Nevertheless the first review (Allen, Erdmann & Astria Yusmalinda) was not made until 2016. A great publication to read. Not only because of the information on these fabulous fish, but also to enjoy the beautiful colors of these amazing animals.

Courting males have a spectacular neon-like flasher display. Some species, including the P. filamentosus pictured hereby, have wonderful filamentous dorsal fins. These gorgeous colors and fins are seen in terminal phase (TP) males only. Like most other labrid fishes, the fairies become sexually mature as females known as Initial Phase (IP) fish. The transformed females become TP males which grow larger and more colorful. Paracheilinus are know to form aggregations of tens to hundreds of individuals. The larger TP males defend a harem of females. The color patterns associated with their nuptial display, are used as diagnostic feature for the species. The approximately 20 species which are nowadays  known, are divided into two categories. The filamentosus-group is characterized by the elongated dorsal finrays.

References
Allen, Gerald R.; Mark V. Erdmann & Niluh Astria Yusmalinda (2016): Review of the Indo-Pacific Flasherwrasses of the genus Paracheilinus (Perciformes: Labridae), with descriptions of three new species. - Journal of the Ocean Science Foundation, 2016, Volume 19: 18-90. 

Original artwork available:

Prints of the artwork in this blog can be ordered at my printshop in full and in detailed version (without the white borders).

Last man standing

´Last man standing´ was the first thriller I have read from David Baldacci, way back in 2001 or 2002. Does it matter? Not really as the title above this blog refers to something else and maybe, just maybe, I should have used the title 'Last fish swimming'. However. 'Last man' is the expression (although 'last fish' does sound far more dramatic and would be appropriate for the occasion). The fish pictured above is Cyprinodon inmemoriam. A male specimen; first caught specimen of its kind and... last specimen of its kind. How's that?

The discovery of C. inmemoriam is an impressive story to read, from the first discovery of the habitat in Mexico (by photos one of the authors made during a commercial flight above the area in 1983) to the dramatic conclusion of its extinction. The dry Bolsón de Sandia (Pluvial Lake Sandia) is a dry lake bed of unknown age. The area has several springs in which four new species were discovered:
C. ceciliae, collected in 1988 at Ojo de Agua La Presa
C. inmemoriam, collected in 1984 at Ojo la Trinidad
C. longidorsalis, collected in 1988 at Charco la Palma
C. veronicae, collected in 1984 at Ojo de Agua Charco Azul

The four Cyprinodons are considered to be a monophyletic lineage; an assemblage of species with characters shared with C. alvarezi. All four species share the remarkable coloration of the eye, which includes two rings (a gold inner circle and a pale yellow outer circle). The only specimen of C. inmemoriam was a male specimen (57.3mm). Whereas the males of all four species have metallic blue colors on their body, this male showed pale grey blue coloration with obsolete bars. Colors in Cyprinodon males differ during the season. As no females of C. inmemoriam were found, the male specimen probably did not show its best colors. Why dress up if there's noone to impress eh?

During the study by Lozano-Vilano and Contreras-Balderas two of the four springs dried up and the inhabitants (C. ceciliae and C. inmemoriam) presumably became extinct. In Ojo la Trinidad no fish have been found since 1985; the spring fully dried in 1986. That's how the one and only specimen of C. inmemoriam got his name ('inmemoriam' = remember after death). A unique endemic crayfish, Cambarellus sp., found at the same spring has not been described and also is considered extinct.

So; end of story? The chance of living specimens of C. inmemoriam  ever to be found again can be ruled out. We'll have to settle with the unique holotype (deposited at the Universidad Autónoma de Nuévo Leon; Mexico). The population of C. ceciliae is only known from Ojo de Agua La Presa; this spring nearly dried during the winter of 1991. Attempts to find specimens when the water returned in 1992 failed; since then this species is also considered to be extinct.
The other two endemic species, C. longidorsalis and C. veronicae, are considered to be endangered due to agricultural overexploitation of the groundwater. Thus, the story of this unique lineage of species does not have to end. However, the chances of survival are very limited.

References: 
Lozano-Vilano, M. de L. and S. Contreras-Balderas  (1993): Four new species of Cyprinodon from southern Nuevo León, Mexico, with a key to the C. eximius complex (Teleostei: Cyprinodontidae). - Ichthyological Exploration of Freshwaters v. 4 (no. 4): 295-308.

Original artwork available:

Prints of the artwork in this blog can be ordered at my printshop in full and in detailed version (without the white borders).