Danionella cerebrum

biology_ecology

Habitat. Allwaterbodiesinwhich Danionellacerebrum wasfound, areturbidlowaltitudestreams (Fig. 3) with visible flow, surface temperatures of around 30 ° C, pH 7.4 – 7.5 and sof water of 20 – 100 micro Siemens. Danionellacerebrum was not found at the surface, but at adepth below ca. 30 cm where the water is significantly cooler (ca. 25 ° C). Te species was abundant at the type locality in Hmawbi on 18 Oct 2008, where it co-occurred with D. translucida (as evidenced by c & s specimen and DNA sample), which appears to have been less common (a single c & s D. translucida among 28 D. cerebrum). At Daikme Chaung (Fig. 3), the type locality of D. translucida, D. cerebrum was uncommon (1 out of 27 c & s specimens of Danionella) on 19 Aug 2008, but D. translucida was abundant.

The emerging vertebrate model species for neurophysiological studies is Danionella cerebrum, new species (Teleostei: Cyprinidae)

description

Additional material (non type): MTD 39990, 29 specimens, 7.8 – 11.5 mm SL, aquarium shop in Bago, reportedly from Tandabin Chaung, Britz et al., 19 Oct 2008. MTD 39991, 8 c & s, 8.5 – 11.3 mm SL, aquarium shop in Bago, reportedly from Tandabin Chaung, Britz et al., 19 Oct 2008.

The emerging vertebrate model species for neurophysiological studies is Danionella cerebrum, new species (Teleostei: Cyprinidae)

description

Description. Maximumknownsize 13.5 mmSL. GeneralbodyshapeillustratedinFig. 1 a – d. Morphometric information based on 10 specimens is provided in Table 2. Head and eye are large; mouth supraterminal. Nostrils well developed. Lateral line canals and pores on head and body absent. Body elongate with a short dorsal fin, situated opposite to posterior half of long anal fin. Tip of dorsal fin situated posterior to a vertical line through tip of anal fin. Caudal fin furcate with remnants of larval-fin fold in front of its dorsal and ventral margins. A remnant of pre-anal larval-fin fold present in adult females, absent in adult males. Anus and genital papilla of mature males located between pelvic fins, at normal position in front of anal fin in females and in immature males between pelvic and anal fins. Awindow (pseudotympanum) present in body musculature at lateral side of anterior swim bladder chamber, rendering its pigmented surface visible. Scales absent. Figure 2. Comparisonofskeletalcharactersofclearedandstainedfemalesof Danionellacerebrum, and D. ▸ translucida. Whole skeleton of D. cerebrum (a), MTD 39986, paratype, 11.5 mm SL and D. translucida (b), MTD 39992, 13.1 mm SL in late

The emerging vertebrate model species for neurophysiological studies is Danionella cerebrum, new species (Teleostei: Cyprinidae)

diagnosis

Diagnosis. Danionellacerebrum isdistinguishedfrom D. translucida, D. dracula, and D. priapus bythenumber of anal-fin rays (15 – 18 vs. 12 – 15 in D. translucida, 12 – 14 in D. dracula, 20 – 21 in D. priapus, Table 1). It is further distinguished from D. mirifica, D. dracula, and D. priapus by fewer vertebrae (33 – 35 vs. 36 – 38, Table 1), from D. priapus and D. dracula by fewer pectoral-fin rays (6 vs. 8 in D. priapus and 7 in D. dracula, Table 1), from D. translucida and D. dracula by the presence of a ventromedially directed cartilage flange from the taenia marginalis anterior that approaches the trabecula communis (vs. absence, Fig. 2 c, d), and from D. dracula by the presence in the male of bony flanges on the outer arm of the os suspensorium and a connection of these to the lateral process of vertebra 2 (vs. absence of flanges and of connection to second lateral process), the presence of a maxillo-mandibular cartilage (vs. absence), the absence of odontoid processes in the male (vs. presence), more anal-finpterygiophores (14 – 17 vs. 11 – 13, Table 1), more principalcaudal fin rays (9 + 9 vs. 8 + 8, Table 1) and fewer pelvic-fin rays (5 vs. 6, Table 1). Danionella cerebrum ca

The emerging vertebrate model species for neurophysiological studies is Danionella cerebrum, new species (Teleostei: Cyprinidae)