• Animal cells and systems
• /
• v.3 no.4
• /
• pp.407-412
• /
• 1999

The influence of eating habits and food type on the ultrastructural characteristics of the digestive tracts was studied under the scanning and transmission electron microscopes in two crustacean decapods (Hemigrapsus penicillatus De Haan; mud crab, Pinnotheres cyclinus Shen; symbiotic crab). The relative ratio of the length of midgut versus hindgut was 1:1 in the mud crab, but 4:1 in the symbiotic crab. Observation through the scanning electron microscope revealed that the midguts of both species have densely-arranged longitudinal mucosal folds with a smooth surface. In the hindgut of the mud crab, mucosal folds were longitudinally oriented, clusters of two to five spines were observed on the cuticular surface, and the length of the spine in the distal hindgut was longer than that in the proximal portion. In the symbiotic crab, the mucosal folds were irregulary arranged, and numerous rudimentary spinal structures were noted on the cuticular surface. Through observation of a transmission electron microscope, the epithelial cells of the midgut in both species had numerous microvilli, but the length of the microvilli was slightly longer in the mud crab than in the symbiotic crab. The central layer of the basement membrane and the muscular layer of the midgut were more developed in the mud crab than in the symbiotic crab. The thickness of the cuticular layer over the hindgut surface in the mud crab was about 4 times than that of the symbiotic crab.

• Animal Systematics, Evolution and Diversity
• /
• v.26 no.3
• /
• pp.337-339
• /
• 2010

A hole dwelling holothurian symbiotic crab was collected in the low tidal mark in Namhae Island. The crab was identified as Asthenognathus inaequipes Stimpson, 1858 and found to be new to Korean waters. The species was briefly illustrated and described.

• The Korean Journal of Zoology
• /
• v.34 no.3
• /
• pp.289-299
• /
• 1991

Two new species of the genus Hemicyclops, H. 형omsoensis n. sp. and H. soxatilis n. sp., taken from crab burrows on each of mud flat and rocky shore, are described from the Yellow Sea coast of southwest Korea.

• Animal Systematics, Evolution and Diversity
• /
• v.25 no.1
• /
• pp.125-128
• /
• 2009

The crinoid symbiotic crabs, Harrovia japonica were collected for the first time from Geomundo Island in Korea. At present, there are two species of the Eumedoninae in Korean waters.

• Animal Systematics, Evolution and Diversity
• /
• v.7 no.2
• /
• pp.257-264
• /
• 1991

The first zoea of Pinnotheres sinensis showed the characteristics which were correspond well with those of Pinnotheres zoeae ; No carapace spines, endopodites of maxillule and maxilla with 0.4, 1.2(3) setation and endopodite of second maxilliped with 0.4 setation. However, the setations of the basal and coxal endites of the maxillule and maxilla was different from those of Muraoka and Konishi (1977), Konishi(1983).The host of adult crab was Tapes, not mytilus . Thus, there was a need for detailed description of the Korean crab of Pinnotheres sinensis symbiotic with Tapes.

• Animal Systematics, Evolution and Diversity
• /
• v.32 no.2
• /
• pp.112-117
• /
• 2016

We studied the ectosymbionts associating with the sea anemone Stichodactyla gigantea at Kosrae, Micronesia. Ectosymbionts of seven species associated with 60.7% of S. gigantea (n=28), with a mean of 2.4 per anemone and 3.9 per occupied anemone. Anemones hosting one or more ectosymbionts did not differ significantly in size from anemones lacking ectosymbionts and there was no significant correlation between anemone size and the number of ectosymbionts. Of 67 ectosymbionts observed, the sea cucumber Stichopus vastus comprised 23.9%, followed by the shrimp Thor amboinensis (20.9%), unidentified hermit crabs (Paguroidea; 20.9%), the cardinalfish Ostorhinchus novemfasciatus (20.9%), the shrimp Periclimenes brevicarpalis (9.0%), the sea cucumber Holothuria hilla (3.0%), and an unidentified brachyuran crab (1.5%). This study documents the first records of S. vastus, H. hilla, and O. novemfasciatus associating with S. gigantea, and the first locality records of S. gigantea, T. amboinensis, P. brevicarpalis, and S. vastus for Kosrae. Because humans often harvest S. gigantea for food at Kosrae, we recommend protecting the symbiotic assemblage of S. gigantea by establishing a sustainable system of harvesting.