• Animal cells and systems
• /
• v.11 no.1
• /
• pp.51-54
• /
• 2007

The first zoea of Pugettia gracilis is described and illustrated for the first time. Its morphological characteristics are compared with those of other known species of the genus from the northern Pacific waters. Although the Pugettia zoeas of the northwestern and the northeastern Pacifies are very similar, they can be easily distinguished by their dorsal carapace spine. In the northwestern Pacific it is spinulate with a spinous tip, while in the northeastern Pacific it is smooth with a blunt tip.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.4
• /
• pp.304-308
• /
• 2020

Ovigerous crab of Echinoecus nipponicus of subfamily Eumedoninae in Pilumnidae was collected from Seogwipo, Jejudo and hatched in the laboratory. The first zoeal stage of E. nipponicus is reported for the first time in the world and its digital image of live zoeas is provided. The first zoea of E. nipponicus has yellowish red chromatophores which occurring behind eyes, on dorsal spine and on anterior margin of telson, reddish brown chromatophores on abdominal somites 2-5 ventrally, dorsal, rostral, and lateral spines shorter than carapace length, three aesthetascs and two setae on the antennule, two medial setae on the antennal exopod, lateral processes on the abdominal somites 2, 3, and two lateral spine and one dorsomedial spine on the telson.

• Animal Systematics, Evolution and Diversity
• /
• v.38 no.2
• /
• pp.83-90
• /
• 2022

Ovigerous crab of Sphaerozius nitidus of the family Menippidae was collected from Geojedo, Gyeongsangnamdo and hatched in the laboratory. Digital imaging of live zoeas of the first zoea stage of S. nitidus has been reported for the first time in the world, and its morphology has been redescribed and illustrated. This study is different from former study in that it has three unequal setae with exopod of antenna, 5+4 setae with basial endite of maxilla, and dorsomedial spine and lateral minute spine with fork of telson. The first zoea of S. nitidus has black pigments occurring behind the eyes, on the dorsal spine medially and on the basis of lateral carapace spines, on basal of basis of maxillipeds 1, 2, and posterior margins of somites 1-5, and yellowish green chromatophores on the dorsal spine.

• Animal cells and systems
• /
• v.8 no.4
• /
• pp.251-254
• /
• 2004

The first zoea of Petrolisthes trilobatus Osawa, 1996, from a female collected in Japan is described and illustrated. Its morphological characteristics are compared with those of other known species of the genus Petrolisthes. The first zoea of P. trilobatus appears very similar to those of P. lamarckii, P. asiaticus and P. hastatus. However, it could be distinguished from the others in having a spine on the lower posterior margin of the carapace, three pairs of setae on the postero-dorsal surface of the telson and minute spinules on the dorsal margins of the abdominal somites 2-5. Based on zoeal morphology, it is suggested that the zoeas of Petrolisthes could be divided into two groups: the first group (P. coccineus, P. moluccensis, P. lamarckii, P. trilobatus, P. asiaticus, P. hastatus, P. pubescens, P. tomentosus, and P. carinipes) and the second one (P. ohshimai, P. armatus, P. boscii, P. tridentatus, P. tonsorius, and P. japonicus).

• Animal cells and systems
• /
• v.5 no.1
• /
• pp.11-15
• /
• 2001

The first zoeal stage of Enosteoides ornata (Stimpson, 1858) is described and illustrated in detail. Its morphological characteristics are compared with those of other known species of the family Porcellanidae. In the family Porcellanidae its diagnostic characteristics are the exopod of an antenna armed with a seta and five spinules and the coxa of the first maxilliped having two setae. The former characteristic can be seen in most of the genus Petrolisthes zoeas, while the latter usually in the genus Pachycheles zoea. The Enosteoides ornata seems to be p1aced intermediately between the genus Pachycheles and the genus Petrolisthes based on the zoeal morphology.

• Animal Systematics, Evolution and Diversity
• /
• v.18 no.2
• /
• pp.191-201
• /
• 2002

The first zoeal stage of Heptacarpus rectirostris (Stimpson, 1860) is re-described and illustrated in detail from laboratory-hatched material. The first zoea of H. rectirostris is more closely related to that of H. futilirostris than to H. camtschaticus, H. pandaloides, and H. geniculatus by having the pterygostomial spine and two anteroventral denticles on the carapace. The former two species, however, can be readily distinguished by the presence (H. futilirostris) or absence (H. rectirostris) of the posterolateral spine on the abdominal somites 4-5. A provisional key to the first zoeas of Heptacarpus for which larval studies are known from Korea and adjacent waters is provided. A list of larval descriptions within the Hippolytidae from Korea and adjacent waters is also included.

• Animal Systematics, Evolution and Diversity
• /
• v.21 no.2
• /
• pp.193-199
• /
• 2005

The first zoea of Liomera bella belonging to the subfamily Liomerinae is described and illustrated for the first time. Its morphological characteristics are compared with those of other known species of the Xanthidae The general morphology of it corresponds well with zoeas of the Xanthidae. Based on the zoeal morphology, the zoea of L. bella shows a greatest affinity with those of Xontho incisus and Pseudomedaeus agassizii by having the exopod of antenna with two setae, the terminal segment of the endopod of the second maxilliped with six setae, and the fork of telson with one stout and one smaller lateral spines.

• Journal of Aquaculture
• /
• v.5 no.1
• /
• pp.29-67
• /
• 1992

Life cycle and seed production of the freshwater prawn, Macrobrachium nipponense, were studied and the results are as follows : 1. Larval development : Embryos hatched out as zoea larvae of 2.06 mm in mean body length. The larvae passed through 9 zoea stages in $15{\~}20$ days and then metamorphosed into postlarvae measuring 5.68 mm in mean body length. Each zoea stage can be identified based on the shapes of the first and second antennae, exo- and endopodites of the first and second pereiopods, telson and maxillae. 2. Environmental requirements of zoea larvae : Zoea larvae grew healthy when fed with Artemia nauplii. Metamorphosing rate was $65{\~}72{\%}$ at $26{\~}28\%$ and $7.85{\~}8.28\%_{\circ}Cl.$. The relationship between the zoeal period (Y in days) and water temperature (X in $^{\circ}C$) is expressed as Y=46.0900-0.9673X. Zoeas showed best survival in a water temperature range of $26{\~}32^{\circ}C$ (optimum temperature $28^{\circ}C$), at which the metamorphosing rate into postlarvae was $54{\~}72\%$ The zoeas survived more successfully in chlorinity range of $4.12{\~}14.08{\%_{\circ}}Cl.$, (optimum chlorinity $7.6{\~}11.6\;{\%_{\circ}}Cl.$.), at which the metamorphosing rate was $42{\~}76{\%}$. The whole zoeal stages tended to be longer in proportion as the chlorinity deviated from the optimum range and particularly toward high chlorinity. Zoeas at all stages could not tolerate in the freshwater. 3. Environmental requirements of postlarvae and juveniles : Postlarvae showed normal growth at water temperatures between $24{\~}32^{\circ}C$ (optimun temperature $26{\~}28^{\circ}$. The survival rate up to the juvenile stage was $41{\~}63{\%}$. Water temperatures below $24^{\circ}C$ and above $32^{\circ}$ resulted in lower growth, and postlarvae scarcely grew at below $17^{\circ}C$. Cannibalism tended to occur more frequently under optimum range of temperatures. The range of chlorinity for normal growth of postlarvae and juveniles was from 0.00 (freshwater) to $11.24{\%_{\circ}}Cl.$, at which the survival rate was $32{\~}35\%$. The postlarvae grew more successfully in low chlorinities, and the best growth was found at $0.00\~2.21{\%_{\circ}}Cl.$. The postlarvae and juveniles showed better growth in freshwater but did not survive in normal sea water. 4. Feeding effect of diet on zoea Ilarvae : Zoea larvae were successfully survived and metamorposed into postlarvae when fed commercial artificial plankton, rotifers, and Artemia nauplii in the aquaria. However, the zoea larvae that were fed Artemia nauplii and reared in Chlorella mixed green water showed better results. The rate of metamorphosis was $68\~{\%}75$. The larvae fed cow live powder, egg powder, and Chlorella alone did not survive. 5. Diets of postlarvae, juveniles and adults : Artemia nauplii and/or copepods were good food for postlarvae. Juveniles and adults were successfully fed fish or shellfish flesh, annelids, corn grain, pelleted feed along with viscera of domestic animals or fruits. 6. Growth of postlarvae, juveniles and adults : Under favorable conditions, postlarvae molted every five or six days and attained to the juvenile stage within two months and they reached 1.78 cm in body length and 0.17 g in body weight. The juveniles grew to 3.52 cm in body length and 1.07 g in body weight in about four months. Their sexes became determinable based on the appearance of male's rudimental processes (a secondary sex character) on the endopodites of second pereiopods of males. The males commonly reached sexual maturity in seven months after attaining the postlarvae stage and they grew to 5.65 cm in body length and 3.41 g in body weight. Whereas the females attained sexual maturity within six to seven months, when they measured 4.93 cm in body length and 2.43 g in body weight. Nine or ten months after hatching, the males grew $6.62{\~}7.14$ cm in body length and $6.68{\~}8.36$ g in body weight, while females became $5.58{\~}6.08$ cm and $4.04{\~}5.54$ g. 7. Stocking density : The maximum stocking density in aquaria for successful survival and growth was $60{\~}100$ individuals/$\ell$ for zoeas in 30-days rearing (survival rate to postlarvae, $73{\~}80{\%}$) ; $100{\~}300$ individuals/$m^2$ for postlarvae of 0.57 cm in body length (survival rate for 120 days, $78{\~}85{\%}$) ; $40{\~}60$ individuals/$m^2$ for juveniles of 2.72 cm in body length (survival rate for 120 days, $63{\~}90{\%}$) : $20{\~}40$ individuals/$m^2$ for young prawns of 5.2 cm in body length (survival rate for 120 days, $62\~90{\%}$) ; and $10\~30$ individuals/$m^2$ for adults of 6.1 cm in body length (survival rate for 60 days, $73\~100{\%}$). The stocking density of juveniles, youngs and adults could be increased up to twice by providing shelters.