Spontaneous captive breeding and larval development in the green and red variants of the Japanese sea cucumber Apostichopus japonicus (Selenka 1867)

We report the spontaneous spawning, larval development, survival rate and larval growth rate patterns observed in the green and red variants of the Japanese sea cucumber Apostichopus japonicus. The green variant adapted well to the captive conditions in the Sasebo City Fisheries Center and spontaneously spawned without any induction or stimulation. One hundred individual green variants spawned nine times and produced approximately 155 million eggs. In contrast, 50 individual red variants showed poor adaptation to captivity and spawned spontaneously only three times, producing about 12 million eggs. Larval development and growth rate pattern was almost identical between the two variants of A. japonicus. In contrast, the larval survival rate for the green variant was over 90% up to the auricularia stage (10 days), but much low (less than 30%) for the red variant. We demonstrated that the green variant of A. japonicus was easier to rear in captivity. This provides a useful method for maintaining sustainable harvests and eventually contributing to restocking and sea ranching of the existing population. Further studies about optimal ecological conditions and behaviour are needed to improve egg production and survival rate of the red variant of A. japonicus.     

Some morphological and anatomical studies of leaves and flowers of Murraya paniculata (Jack) Linn. in vivo and in vitro

In the present study, various explants of Murraya paniculata (Jack) Linn., such as cotyledons, shoots and young stems were cultured on MS medium supplemented with various concentrations of Benzyl Amino Purine (BAP) under 25 +/- 1 degree C with 16 h light and 8 h dark and also 8 h light and 16 h dark to obtain complete plant regeneration. In vitro flowering was observed from shoot explants cultured on MS supplemented with 0.5-2.0 mg L(-1) Naphthalene Acetic Acid (NAA) and also on MS basal medium under similar conditions. The leaves and flowers obtained from both in vivo and in vitro conditions were examined and compared. Morphological studies such as leaf clearing, epidermal peeling were studied using light and scanning electron microscope. Macromorphological studies of the flowers produced from in vivo and in vitro conditions were also examined. Morphologically, there were no differences between in vivo and in vitro flowers except the flowers produced from tissue culture systems were smaller in size with protruding stigmas. Differences were also found in the number of layers of palisade cells and the presence or absence of epicuticle layer of the leaves. Leaves produced from tissue culture system were smaller in size with membranous texture. Stomata were present only on the abaxial surfaces of both in vivo and in vitro leaves but the stomata were raised above the epidermis in the latter.     

Plant regeneration and floral bud formation from intact floral parts of African violet (Saintpaulia ionantha H. Wendl.) cultured in vitro

Intact immature flower buds of African violet (Saintpaulia ionantha H. Wendl.) were used as explant sources for in vitro studies. The effect of exogenous hormones, NAA and BAP on the indirect organogenesis of this species was observed. Callus was formed on the cut end (base) of pedicels of floral buds where they were in contact with the medium. When maintained on the same medium, callus was differentiated into adventitious shoots after 10 weeks in culture. MS media supplemented with 2.0 mg L(-1) NAA and 1.0 mg L(-1) BAP gave the highest number of sterile or vegetative floral buds from the surface of callus of the explants, but these buds failed to develop further. The floral buds were expanded as abnormal flowers. The floral structures were smaller in size compared to intact flowers. Petals (corolla) were white to purple in colour but did not form any reproductive organs, i.e., stamens or pistils. All sterile or vegetative floral buds and abnormal flowers survived for 3 months in culture but failed to reach anthesis.     

Light and electron microscopic study of the thyroid gland of the camel (Camelus dromedarius)

The thyroid gland of sexually immature dromedary camels was studied using both light and electron microscopy. The thyroid gland contained follicles of different sizes in both summer and winter. However, most of the follicles were large in summer and small in winter. The large follicles were lined by very low cuboidal or semi-squamous follicular cells whereas the small ones were lined by high cuboidal or low columnar follicular cells. Electron microscopy showed that the very low cuboidal follicular cells were poor in organelles and were considered hypoactive. High cuboidal follicular cells on the other hand, were rich in organelles that included mitochondria, cisternae of rough endoplasmic reticulum, secretory vesicles, colloid droplets, heterosomes and autophagic vacuoles; they were considered to be very active. The possible role played by these organelles is synthesis of thyroglobulin and liberation of tri- and tetraiodothyronine is discussed. A few degenerate follicular cells were infrequently encountered in the camel thyroid. Parafollicular (C) cells were not seen in this study either with light or electron microscopy.     

The parotid, mandibular and lateral retropharyngeal lymph nodes of the camel (Camelus dromedarius)

The parotid, mandibular and lateral retropharyngeal lymph nodes of the dromedary camel were examined using both light and electron microscopy. All three lymph nodes were lobulated. They did not show the characteristic medulla, cortex and paracortex of typical lymph nodes. Instead, they contained lymphatic nodules, dense anodular lymphoid tissue and diffuse lymphoid tissue dispersed throughout the lymph node. Networks of sinuses were present in the diffuse lymphoid tissue. The diffuse lymphoid tissue in the periphery of all lymph nodes examined was characterized by numerous erythrocytes within and around its network of sinuses. The nodal sinuses were contiguous with the septal vessels, which are considered the possible source of erythrocytes seen in this study. The lymph nodes that were seen in this study resembled the haemolymph nodes of other mammals with regard to their content of erythrocytes but were unique in being located in sites that were typical of ordinary lymph nodes. Morphometric analysis has shown that the percentage volume densities of the stroma and the various parenchymal components were similar in the three lymph nodes.     

The optimized inclusion level of Bacillus subtilis fermented Azolla pinnata in Nile tilapia (Oreochromis niloticus) diets: immunity,antioxidative status,intestinal digestive enzymes and histomorphometry,and disease resistance

Fish Physiology and Biochemistry - A 95-day feeding trial was conducted to evaluate the outcomes of feeding Bacillus subtilis fermented Azolla (BSFA) on nonspecific immunity, antioxidative status,...