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).

Triggered

Triggerfish are diamond shaped fish with a trigger-like dorsal fin, or actually dorsal spine, which they can raise and retract into a groove in their back. In case of danger this spine pops up and looks like the trigger of a revolver. At night the spine is also used to secure their body between rocks and corals. Triggerfish do most of their swimming by slowly rolling their broad dorsal and ventral fins, rather than by flexing their whole body like many other fish.

Fishes adapt to their aquatic environments; maximizing their efficiency for foraging, mating, and escaping predators (or: catching prey). Speed and acceleration are necessities in predator/prey interactions; i.e. manoeuvrability is king when you need to escape predator attacks. Fishes have produced a great diversity of forms that differ in their propulsive mechanisms using the body, caudal fin, pectoral fins, and median (dorsal and anal) fins. Several species have evolved into deep-bodied specialists using non-caudal propulsion. This adaptation may benefit in a number of ways: manoeuvrability in complex environments (like coral reefs) and at higher speeds, and specialization in acceleration to escape from predators.

Coral reefs are an environment where defensive armour (like the thick impenetrable skin of seahorses) has developed at the expense of speed. Moving around the complex habitat of coral reefs requires exact manoeuvring. Large predators (like sharks) lack the fine control to navigate within this environment. Reef fish must be able to situate their bodies in any number of directions, including the ability to swim backwards effectively and to turn in small radius circles. Triggerfish, the sole species of the family Balistidae and “type form” for balistiform locomotion, use their dorsal and anal fins as their sole method of propulsion at speeds up to half of their maximum swimming velocity. In order to swim backwards, triggerfish reverse the wave on their median fins providing a very efficient method of swimming backwards.

The first triggerfish to gain popularity for aquariums, and still one of the most popular triggerfish, is Rhinecanthus aculeatus, the Picasso triggerfish. The name refers to the fish’s striking coloration, its geometry and its prominent eyes, much like the cubistic art of the Spanish painter Pablo Picasso. The Picasso triggerfish is distinguished by the set of black and blue stripes between its independently working eyes over the top of the head and the vertical yellow band leading from the mouth to below the eye on its cream-colored body.

References
Loofbourrow, Hale (2009): Hydrodynamics of Balistiform swimming in the Picasso triggerfish, Rhinecanthus aculeatus. - Thesis, University of British Columbia (Vancouver): 1-81.

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).

Psycho kid

Juvenile fish often are not exact look-a-likes of their parents. Instead they show completely different coloration and behavior. Why? Mostly because it can be beneficial for the kids not to look like their parents. Many fish consider any fish with pigmentation; a color pattern and a body shape similar to their own as competitive.  So, being young, lean and mean juveniles often opt for an outfit which does not resemble the wardrobe of the adults of their species. Looking nothing like your parents increases the chance adults will tolerate your presence (and maybe even your behavior) in their territory. 

Adult Emperor Angelfish (Pomacanthus imperator) show yellow and blue stripes on their sides; white, black and yellow coloration around the head; a mask across the eyes and a bright yellow caudal fin. Does the image of the young specimen I painted look like the adults at all? Nope; juvenile Emperors have a dark blue almost black base color with light blue and white lines which form vertical stripes and concentric circles on their flanks. The development of the pigmentation (and stripe) pattern in juvenile Angelfish has been studied (e.g. Painter, Maini & Othmer, 1999); proving the consistency of the formation of the stripings, starting with two vertical lines and developing into a more or less psychedelic pattern (as in the young Emperor I copied in paint). 

The 'special outfit' in some juvenile Angelfish (i.e. Pomacanthus paru in  Sazima, Moura & Sazima, 1999) has been proven to be an advertisement for their specialization: 'cleaning' fish. So, beside enabling them to live close to their parents; the juvenile coloration also is a significant signal to warn other fish:"Hey there! I can clean you!". A great way to obtain a free meal. And, last but not least, an additional warning to predators: "Hey there, I will clean you, don't eat me!"
Have you ever? Psycho kids that do clean their room!

References
Sazima, Ivan; Rodrigo L. Moura & Cristina Sazima (1999): Cleaning activity of juvenile Angelfish, Pomacanthus paru, on the reefs of the Abrolhos Archipelago, Western South Atlantic. - Environmental Biology of Fishes, Dec.1999, Volume 56, Issue 4: 399-407. 

Painter, K.J.; P.K. Maini & H.G. Othmer (1999): Stripe formation in juvenile Pomacanthus explained by a generalized mechanism with chemotaxis. - Proceedings of the National Academy of Sciences (PNAS), May 1999, 96 (10): 5549-5554. 

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).

Der Hans

Peacock cihlids are some of the most beloved fish in the aquariumhobby. This species, Aulonocara baenschi, was named for a man whose family contributed a lot to this hobby; in all kinds of ways .Hans Albrecht Baensch (September 10, 1941 - November 2, 2016) worked for his father's company: Tetra GmbH. That's right, Ulrich Baensch was the 'inventor' of Tetramin. He was the first to market universal dry food (or staple food) for the aquariumtrade. No matter how many brands have flooded the aquariumtrade; I am sure every aquarist has used his products at least once.

Hans Baensch worked and traveled around the world for Tetra. But he is best remembered by his publications. In 1977 he founded Mergus Verlag, home of the famous Aquarium Atlas which nowadays has 26 volumes including books on fresh and salt water; garden ponds; terrariumhobby and fossils. In the first edition of the Atlas (1985) M.K. Meyer and R. Riehl described this greatlooking yellow and blue Peacock Cichlid, which they hamed for Hans Baensch. In 1987 Meyer, Riehl and Zetzsche named another cichlid in his honor: Aulonocara hansbaenschi; however this species has been synonimsed by Konings (2016) with A. stuartgranti; named for another well known man in the aquariumhobby, especially amongst cichlidophiles.

References
Eschmeyer, W. N.; R. Fricke and R. van der Laan (eds) (2018): 'Catalog of Fishes: genera, species, references. - Version of 2 March, 2018.
Konings, A. F.  (2016): Malawi Cichlids in their natural habitat. -  Cichlid Press, El Paso (TX), 5th Edition: 1-447.

The original is for sale:

The artworks in this blog can be ordered at my printshop. The painting (sand and acrylics on canvas) is available in full (as pictured above) or in detail (without the white borders).

Fish in space

Science Fiction stories and, as we speak, Fantasy stories too, often include bizarre creatures which readers believe to have derived from the author's mind; whereas many of these exotic animals in fact are based on species that once lived, or are still living, on good old planet Earth. The world of wildlife is beyond imagination and provides an incredible variety of lifeforms useable to any writer. Yep, an endless goldmine of inspiration.

Besides the living creatures themselves; their names also provide inspiration. The huge number of species is organized and described by scientists.  And oh, what fun they have! Describing new species scientists come up with fantastic names. I have kindly used one of these names, Celestichthys, as the name of a space vessel in a short SF story I recently finished (´Innerverse´). Celestichthys, meaning ´heavenly fish´, is a name especially composed for a gorgeous little fish, described as Celestichthys margaritatus, which has become very popular in the aquarium trade as Celestial Pearl Danio, CPD in short, and is also known as Galaxy Rasbora, Fireworks Rasbora and several more vernacular and even pseudo scientific names. Described in 2007, this species profited from the hype in aquaristics: Nano Cubes. Small aquariums designed for small fish and invertebrates. The impressive name of Celestichthys didn't stand for a long time. In 2008 Conway replaced the tiny, hardly 2.5 cm long fish with its dark blue body, covered with multiple yellow-white spots, into the genus Danio.

Alas, rumor had it, the small beauties were imported in such large numbers they had become extinct in their natural habitat, isolated small, heavily vegetated pools at the foot of a mountain near Hopong town 30km south of Taunggyi in Myanmar. And, alas again, nothing travels the internet as fast as rumors. Luckily this cyberspace confusion soon appeared to be untrue. Facts and figures were based on supposed data; fantasies if you like. Fiction lost this battle from reality: instead of living in a restricted area the Galaxy Rasbora is now known to occur in waters associated with the Salween (or Thanlwin) River throughout Shan (Myanamar) and even across the border in northern Thailand. 

Why did I use this name in a SF story? I have known the Galaxy Rasbora almost from the moment it was introduced in the aquariumhobby. I had the pleasure of keeping and breeding them for several years, being one of the first breeders in Europe. Despite their small size they are fun to keep. Even in community tanks, provided the aquarium is not overpopulated, juveniles will soon pop up. As I was writing this SF story, I was in need of a name for a space cruiser. Celestichthys came to my mind; after finishing the story I was even more convinced I had chosen wisely. Even considered it to be the title of the story for a while, but... eh; once you have read my twisted tale you will understand why I have chosen differently.

References
Conway, K. W., W.-J. Chen and R. L. Mayden (2008): The "Celestial Pearl danio" is a minature Danio (s.s.) (Ostariophysi: Cyprinidae): evidence from morphology and molecules. -  Zootaxa No. 1686: 1-28.

Roberts, Tyson R.  (2007): The "Celestial Pearl Danio", a new genus and species of colourful minute cyprinid fish from Myanmar (Pisces: Cypriniformes). - Raffles Bulletin of Zoology, Vol. 55 (no. 1): 131-140.

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).