Nutrient enrichment and probiotics for sea urchin Anthocidaris crassipina larvae in captivity to promote large-scale aquaculture.

Sea urchin contains physiologically active substances, such as amino acids and unsaturated fatty acids, and an important aquatic organism. Purple sea urchin, one of the common edible sea urchins, is an important aquatic product. In order to supply the vast seafood market, large-scale aquaculture of sea urchins is very important. The aim of this study was to optimize the rearing of the Anthocidaris crassipina larvae enhancing the nutrition by mixing feed to improve their growth and survival. The survival rate of Chaetoceros muelleri feeding alone is only 40%. If the survival rate is improved through nutrient enrichment, the large-scale aquaculture of larvae can be promoted. The experiment was divided into two parts. Experiment 1: Two types of commonly used microalgae, Isochrysis galbana tml (I), C. muelleri (C) and two types of probiotics, Rhodopseudomonas palustris (R), and Saccharomyces cerevisiae (S) were used in the. Feeding amounts are 5000, 10,000, and 20,000 cell mL-1, and the control group (N) did not eat. Experiment 2: C. muelleri 20,000 cell mL-1 was mixed with I. galbana tml, R. palustris (R) and S. cerevisiae (S) at 5000 and 10,000 cell mL-1. After the experiment, body length, body width, stomach length, rudiment length, rudiment length, body composition, digestive enzymes and survival rate were measured to evaluate the best feed. The results showed that the mixed feeding of C. muelleri 20,000 cell mL-1 and R. palustris 5000 cell mL-1 can achieve the best development and survival of larval embryos and can promote metamorphosis into juveniles in the shortest time. The research results will be applied to the large-scale aquaculture of A. crassipina larvae to promote the diversity of aquaculture.

First case of a reversed Parabothus taiwanensis Amaoka & Shen, 1993 from Taiwan (Pleuronectiformes: Bothidae), with first evidence of situs inversus viscerum in bothid.

Background: Reversed condition is rarely found in most flatfishes in natural environment, except for some certain species. The mechanism controlling the reversals in flatfishes has been studied in some cultivated species, whereas some have only few cases for the entire family and remain unclear. Here, we report the first record of a dextral (reversed) specimen of Parabothus taiwanensis Amaoka & Shen, 1993 collected off southwestern Taiwan recently. It represents the second reversed case ever recorded in Bothidae. We aim to provide a detailed description of this dextral specimen and compared to the sinistral (normal) specimens collected from the vicinity. Methods: Specimens were fixed in 4% formaldehyde and transferred to 70% ethanol for preservation. Meristic and morphometric characters were examined for both dextral and sinistral specimens. Dissections were made on specimens to confirm the position of internal organs. Lastly, X-radiographs were taken to elucidate the osteological features. Results: As a result, no differences of both meristic and morphometric characters were observed between the dextral and sinistral specimens. Nevertheless, situs inversus viscerum is discovered in the dextral specimen for the first time in Bothidae and the sixth record within flatfishes.

Record of the Amarsipa fish (Family Amarsipidae) from Pratas Island, South China Sea.

Two specimens of the rare Amarsipa fish, Amarsipus carlsbergi, were collected from Pratas Island in the northern South China Sea. They represent the first record of Taiwanese EEZ and fill the distribution gap in the northwestern Pacific Ocean between Japan (East China Sea) and Vietnam. The two specimens were identified based on their diagnostic characteristics, including no pharyngeal sacs, a pelvic fin well in front of the pectoral fin, a slender body and other morphology. Detailed data and descriptions of these two specimens, including a description of otolith morphology, are provided.

Evaluation of Clove Extract for Drug Therapy of Ciliate Infection in Coral (Goniopora columna).

In recent years, ciliate infections have caused serious casualties to corals in the ocean. Infected corals die within a short period of time, which not only poses a threat to wild coral reefs, but also has a major impact on large scale aquaculture of coral. Clove is a kind of Chinese medicine with antifungal, antibacterial, antiviral, insecticidal, and other functions. Clove is a natural product. If it can be used in the treatment of coral ciliates, it will reduce this threat to the environment. The clove extract was diluted with sterile seawater to 500 ppm, 1500 ppm, 2500 ppm, 5000 ppm, 7500 ppm, and 10,000 ppm to carry out virulence test on ciliates. The results show that the LC50 value is 1500 ppm, which can cause the death of ciliates in 10 min without causing significant changes in G. columna SOD, CAT, chlorophyll a, and zooxanthellae. In addition, observation of tissue slices revealed that no ciliates and vacuum were found in the G. columna tissue after 10 min of medicated bathing. In summary, 1500 ppm of clove extract can be used for the treatment of coral ciliates.

Coloconger maculatus sp. nov., a species of short-tail eel from eastern Taiwan (Anguilliformes: Colocongridae).

A new species of Coloconger is described from a large female collected off eastern Taiwan. It can be distinguished from congeners by having a large black blotch on rear portion of tail; posterior end of tail white; and combination of characters: head small 15.7% TL; 4 supratemporal pores, middle 2 in pair; 7 supraorbital pores, 2 pores over posterior nostril; 12 or 14 infraorbital pores; 14 preoperculomandibular pores; 226 dorsal-fin rays and 122 anal-fin rays; preanal vertebrae 77 and total vertebrae 145; rictus through a vertical of posterior margin of pupil; snout shorter than eye diameter; distance between origins of pectoral and dorsal fins 69.4% pectoral-fin length; and body brownish gray dorsally, light gray ventrally, and dorsal fin dark gray. Data and variations of Coloconger japonicus found in Taiwan are provided and discussed.

Probiotic, Lactobacillus pentosus BD6 boost the growth and health status of white shrimp, Litopenaeus vannamei via oral administration.

This study aims to assess and determine the oral-administration of probiotic, Lactobacillus pentosus BD6 on growth performance, immunity and disease resistance of white shrimp, Litopenaeus vannamei. Lac. pentosus BD6 effectively inhibited the growth of aquatic pathogens, which was used in the test. Shrimp were fed with the control diet (without probiotic supplement) for 60 days and the probiotic-containing diets at 107, 108, 109, and 1010 cfu kg-1, respectively. Shrimp fed with the diet containing probiotic at the doses of 109-10 cfu kg-1 showed significant increase in growth performance as well as feed efficiency than that of the control. After a challenge test with Vibrio alginolyticus, shrimp fed with a probiotic diet at a dose of 1010 cfu kg-1 showed a significantly lower mortality as compared to the control and that of shrimp fed the diet containing probiotic at the levels up to 107-8 cfu kg-1. In addition, a therapeutic potential of Lac. pentosus BD6 was discovered because the cumulative mortalities of shrimp fed with probiotic and pathogen V. parahaemolyticus simultaneously were significantly lower when compared to control shrimp. Probiotic in diet at a dose of 109-10 cfu kg-1 significantly increased PO activity of shrimp, while shrimp receiving probiotic at the doses of 108-10 cfu kg-1 showed significant increase in lysozyme activity and phagocytic activity. Shrimp fed with the diet containing probiotic at the level of 1010 cfu kg-1 also indicated higher gene expression of prophenoloxidase (proPO) I, but not proPO II, lipopolysaccharide and ß-1,3-glucan-binding protein and penaeidin 4. Analysis of the bacterial microbiota of the shrimp intestine revealed that oral administration of probiotic increased the relative abundance of beneficial bacteria and reduced the abundance of harmful pathogenic bacteria in the gut flora of shrimp. Despite no statistically significant difference, an analysis of microbial diversity recorded higher species richness, Shannon-Weaver diversity index and evenness in the probiotic group, compared to the control group. It was concluded that Lac. pentosus BD6 has great antibacterial ability against a wide range of pathogens and has therapeutic potential to reduce the mortality of shrimp infected with V. parahaemolyticus. Additionally, dietary Lac. pentosus BD6 at the level of 1010 cfu kg-1 was recommended to improve growth performance, immunity and disease resistance of shrimp against V. alginolyticus.

Transcriptomic analysis elucidates the molecular processes associated with hydrogen peroxide-induced diapause termination in Artemia-encysted embryos.

Treatment with hydrogen peroxide (H2O2) raises the hatching rate through the development and diapause termination of Artemia cysts. To comprehend the upstream genetic regulation of diapause termination activated by exterior H2O2 elements, an Illumina RNA-seq analysis was performed to recognize and assess comparative transcript amounts to explore the genetic regulation of H2O2 in starting the diapause termination of cysts in Artemia salina. We examined three groupings treated with no H2O2 (control), 180 µM H2O2 (low) and 1800 µM H2O2 (high). The results showed a total of 114,057 unigenes were identified, 41.22% of which were functionally annotated in at least one particular database. When compared to control group, 34 and 98 differentially expressed genes (DEGs) were upregulated in 180 µM and 1800 µM H2O2 treatments, respectively. On the other hand, 162 and 30 DEGs were downregulated in the 180 µM and 1800 µM H2O2 treatments, respectively. Cluster analysis of DEGs demonstrated significant patterns among these types of 3 groups. GO and KEGG enrichment analysis showed the DEGs involved in the regulation of blood coagulation (GO: 0030193; GO: 0050818), regulation of wound healing (GO:0061041), regulation of hemostasis (GO: 1900046), antigen processing and presentation (KO04612), the Hippo signaling pathway (KO04391), as well as the MAPK signaling pathway (KO04010). This research helped to define the diapause-related transcriptomes of Artemia cysts using RNA-seq technology, which might fill up a gap in the prevailing body of knowledge.

A new species of the codlet genus Bregmaceros from the western Pacific Ocean (Gadiformes: Bregmacerotidae).

Bregmaceros retrodorsalis sp. nov., a new codlet species is described based on specimens from shallow to deep waters off Japan and Melanesia. It differs from all congeners by having the origin of second dorsal-fin well posterior, above bases of 5th to 7th anal-fin rays and combination of the following characters: a pointed snout distinctly longer than eye diameter; upper lobe of opercle branched distally; body relatively slender, its depth 10.0‒13.0% SL; 13 principal caudal-fin rays (middle 11 branched); 52‒57 second dorsal-fin rays; 58‒63 anal-fin rays; 16‒18 transverse scale rows below dorsal-fin origin; 86‒93 longitudinal scale rows along body axis; vertebrae 55‒58; entire body evenly covered with melanophores, those on lateral sides forming regular longitudinal rows, one melanophores per scale; head and isthmus entirely, but loosely, covered with variably sized melanophores.

Bregmaceros anchovia sp. nov., a new codlet species from the western Pacific Ocean (Gadiformes: Bregmacerotidae).

A new codlet species is described from Japan, Taiwan, Indonesia and Australia. It is distinguished from its congeners by having a pointed snout extending beyond jaws, a stripe of black dots above anal-fin base, a black vertical band on caudal-fin base, and the following combination of characters: ventral surface of head and abdomen devoid of melanophores; ventral portion of abdominal vertebrae with a pointed parapophysis and a blunt ventral post-zygapophysis; peritoneum, pyloric caeca, and intestine pale; dorsal-fin rays 46-52; anal-fin rays 47-55; pectoral-fin rays 15-17; principal caudal-fin rays 12‒14; caudal vertebrae 35‒39; total vertebrae 50-54. Furthermore, as a result of this study, Bregmaceros pescadorus Shen described from southwestern Taiwan is herein recognized as a junior synonym of Bregmaceros nectabanus Whitley.

NMR-based untargeted metabolomic study of hydrogen peroxide-induced development and diapause termination in brine shrimp.

Artemia diapause has been extensively studied in embryonic biology for a long time. It has been demonstrated that hydrogen peroxide (H2O2) can increase the hatching rate in the development and diapause termination of Artemia cysts. This study used an untargeted 1H NMR-based metabolomic approach to explore the physiological regulation of H2O2 in initiating the development and terminating the diapause of Artemia cysts. This experiment was divided into two parts. In the first part, we analyzed three groups with or without H2O2 as control-0h, control-5h and H2O2 (180µM)-5h; in the second part, after 7-d incubation, the non-hatching cysts were treated with different H2O2 concentrations as low as 180µM and as high 1800µM. The results showed that arginine and proline metabolism were up-regulated after 5h, and H2O2 up-regulated valine, leucine and isoleucine biosynthesis in the development of cysts. In the second part, low H2O2 (180µM) showed alanine, aspartate and glutamate metabolism, but high H2O2 (1800µM) also up-regulated arginine and proline metabolism, as in the control group without H2O2 stimulus. These results suggest that enough H2O2 can catalyze cell transcription and translation in Artemia cysts, and it improves the cell growth rate, thus allowing embryo cells to grow again.