Growth and morphological development of laboratory-reared larval and juvenile climbing perch Anabas testudineus

Abstract

Morphological development, including fin and labyrinth organ, body proportions and pigmentation, in laboratory-reared larval and juvenile climbing perch Anabas testudineus was described and behavioral features under rearing condition were observed. Body lengths (BL) of larvae and juveniles were 1.9 ± 0.1 (mean ± SD) mm just after hatching (day-0), 8.7 ± 1.3 mm on day-19, reaching 18.4 ± 2.1 mm on day-35 after hatching. Aggregate fin ray numbers attained full complements in juveniles larger than 8.3 mm BL. Preflexion larvae started feeding on day-2 following formation of the upper and lower jaws, the yolk being completely absorbed by day-7 after hatching. Teeth appeared in flexion larvae larger than 5 mm BL on day-6, with cannibalism starting shortly after and continuing with further growth. Melanophores on the body increased with growth, a large dark spot developing on the lateral midline around caudal margin of the body in the postflexion and juvenile stages. The labyrinth organ differentiated in postflexion larvae larger than 7.2 mm BL on day-16, with air-breathing starting at the same time. Body proportions attained constant in postflexion larvae larger than 7.0 mm BL, and habitat of fish shifted from bottom to mid-layer. With the exception of fin ray numbers, the above morphological developments corresponded to behavioral shifts that occurred in the postflexion stage (ca. 7 mm BL), their subsequent continuity illustrating that the species possessed most juvenile-equivalent functions from ca. 7 mm BL.

Growth and morphological development of laboratory-reared larval and juvenile snakeskin gourami Trichogaster pectoralis

“…Hence, accumulation of early life-history information is essential, including morphological descriptions of indigenous species. Furthermore, since Anabantoidei has long been a systematically contentious taxonomic group, in view of species' diversification and evolutionary ecology (Rüber et al 2006), descriptions of early life-stage morphology should provide significant new information, as only Anabas testudineus has thus been treated so far (Morioka et al 2009). The objective of the present study, therefore, was to facilitate the identification of early life stages of the snakeskin gourami Trichogaster pectoralis.…”

Larval and early juvenile development of silver therapon, Leiopotherapon plumbeus (Actinopterygii: Perciformes: Terapontidae), reared in mesocosms

“…These features are similar to those documented for grouper Epinephelus coioides (Hamilton, 1822) (see Kohno 1998) and orange-spotted spinefoot, Siganus guttatus (Bloch, 1787) (see Avila and Juario 1987). Yolk sac larvae fall under the category of the majority of teleost fishes with diminutive size (<3 mm TL at hatching), similar to those of Leiopotherapon unicolor (Günther, 1859) (see Llewellyn 1973), Eugerres mexicanus (Steindachner, 1863) (see Hernandez et al 2011), and climbing perch, Anabas testudineus (Bloch, 1792) (see Morioka et al 2009). They had undeveloped feeding and sensory structures at hatching.…”

“…Apart from their limited foraging ability (i.e., small mouth gape size), silver therapon larvae have a very brief mixed or transitional phase to exogenous feeding only lasting 15 h (Aya et al 2016), and may, therefore, affect larval survival (Bagarinao 1986, Mookerji andRao 1999). Surviving this 'bottleneck period' is possible if the larvae are equipped with the necessary morpho-anatomical structures for efficient feeding (Utne-Palm 1999, Moteki et al 2001, Morioka et al 2009). Likewise, early pigmentation and active pelagic swimming at this stage promote crypsis strategy to avoid detection by predators (Utne-Palm 1999).…”

“…Morphological studies are important to define metamorphosis, i.e., the transition from larval to juvenile development of fishes, which is often associated with the beginning or end of squamation, and a full complement of fin rays (Nikolioudakis et al 2010). Defining the onset of the early juvenile period requires detailed information on larval and juvenile development (Copp andKováč 1996, Urho 2002), in terms of ontogenetic changes in morphology, growth, pigmentation, and fin formation (Morioka et al 2009). …”

Ontogenetic development in the morphology and behavior of loach (Misgurnus anguillicaudatus) during early life stages

“…Their swimming ability increases after day 5, likely because of the loss of external gill fi laments, development of the fl exuous notochord, and differentiation of pectoral and caudal fi ns. The ability to swim is critical for larval survival during the transition to exogenous feeding (Osse et al, 1997;Gisbert et al, 2002;Morioka et al, 2009). Loach become demersal immediately after hatching and do not have a pelagic larval stage, which differs from many teleost fi sh species (Leis, 2010).…”