Crustaceana

Creed, Robert P.; Lomonaco, Joshua D.; Thomas, Michael J.; Meeks, April; Brown, Bryan L.

doi: 10.1163/15685403-00003418pmid: N/A

<jats:p>The ectosymbiotic branchiobdellidan <jats:italic>Cambarincola</jats:italic> <jats:italic>ingens</jats:italic> Hoffman, 1963 can increase the growth and reduce mortality of the crayfish <jats:italic>Cambarus</jats:italic> <jats:italic>chasmodactylus</jats:italic> James, 1966. These results suggest that these two species are engaged in a cleaning symbiosis mutualism. However, the potential benefits <jats:italic>C. ingens</jats:italic> derives from the association, specifically its reproductive dependence on the crayfish, have not been examined experimentally. We conducted two experiments to determine if <jats:italic>C. ingens</jats:italic> was reproductively dependent on <jats:italic>C. chasmodactylus</jats:italic>. In the experiments, worms only laid cocoons on live crayfish. Also, significantly more cocoons were laid on larger crayfish which was consistent with a survey of worm and cocoon abundance on crayfish collected from a local river. These results suggest that <jats:italic>C. ingens</jats:italic> is dependent on its crayfish host for reproduction. The association between <jats:italic>C. chasmodactylus</jats:italic> and <jats:italic>C. ingens</jats:italic> is a mutualism, at least under environmental conditions in which crayfish survival and growth are enhanced by the worms.</jats:p>

An, Zhenhua; Sun, Longsheng; Wang, Ping

doi: 10.1163/15685403-00003424pmid: N/A

<jats:p>The aim of this study was to determine the acute toxicity effect and the accumulation of microcystin-leucine-arginine (MC-LR) on the crayfish <jats:italic>Procambarus clarkii</jats:italic> (Girard, 1852). Juvenile <jats:italic>P. clarkii</jats:italic> (5.47 ± 1.3 g) were cultured under 5 different MC-LR concentrations (0.3, 0.6, 1.2, 2.4, 4.8 mg/l), then the acute toxicity effect was observed. The median lethal concentration (LC<jats:sub>50</jats:sub>) of MC-LR on juvenile <jats:italic>P. clarkii</jats:italic> was 3.741 mg/l at 24 h, 1.494 mg/l at 48 h, 0.817 mg/l at 72 h and 0.567 mg/l at 96 h. Accumulation of MC-LR was measured in different organs of mature <jats:italic>P. clarkii</jats:italic> (58.7 ± 3.8 g) exposed to 0.3 mg/l MC-LR for 120 h. The detected MC-LR concentration decreased in the sequence: hepatopancreas &gt; ovary &gt; abdominal muscle &gt; intestine. Hepatopancreas and ovary were found to be the main targets of the toxin. The results suggested that the MC-LR produced by cyanobacteria blooms could not only reduce the survival rate of juvenile <jats:italic>P. clarkii</jats:italic> but also affect the fecundity of mature crayfish. This research also provides a reference basis for the detection and assessment of the pollution of water bodies in <jats:italic>P. clarkii</jats:italic> culture.</jats:p>

Kaiser, S. S. M.

doi: 10.1163/15685403-00003417pmid: N/A

<jats:p>Based on benthic material collected during the BIOPEARL (Biodiversity, Phylogeny, Evolution and Adaptive Radiation of Life in Antarctica) II expedition on board RRS “James Clark Ross” a new nannoniscid species,<jats:italic>Regabellator brixorum</jats:italic>sp. n., is described from the Pine Island Bay continental shelf, western Amundsen Sea (Antarctica). The new species most closely resembles<jats:italic>Regabellator armatus</jats:italic>(Hansen, 1916) but can be distinguished from this species by possessing ventral spines on pereonites 1-4, the shape of the cephalothorax anterior margin and the length of the pereonite 7 ventral spine. The genus<jats:italic>Regabellator</jats:italic>has been previously recorded from the North and South-eastern Atlantic and here exclusively from the deep sea (1946 m and below). The new species represents the first record of the genus<jats:italic>Regabellator</jats:italic>from the Antarctic continental shelf and thus greatly extends hitherto known latitudinal and bathymetric ranges for this genus.</jats:p>

Sakai, Katsushi

doi: 10.1163/15685403-00003420pmid: N/A

<jats:p>Up to the present, 31 species of the infraorders Callianassidea Dana, 1852, and Thalassinidea Latreille, 1831 have been reported from the Red Sea area, of which nine, viz.,<jats:italic>Gilvossius bouvieri</jats:italic>(Nobili, 1904),<jats:italic>G. gravieri</jats:italic>(Nobili, 1905),<jats:italic>G. maldivensis</jats:italic>(Borradaile, 1904),<jats:italic>Notiax amboinensis</jats:italic>(De Man, 1888),<jats:italic>Lepidophthalmus rosae</jats:italic>(Nobili, 1904),<jats:italic>Neocallichirus calmani</jats:italic>(Nobili, 1904),<jats:italic>N. indicus</jats:italic>(De Man, 1905),<jats:italic>N. vaugelasi</jats:italic>Dworschak, 2011, and<jats:italic>Podocallichirus madagassus</jats:italic>(Lenz &amp; Richters, 1881), are reviewed in this paper for further unambiguous classification and identification. As a result of this review, one new genus,<jats:italic>Lepidophthalminus</jats:italic>gen. nov. and two new species,<jats:italic>Gilvossius chichijimaensis</jats:italic>sp. nov. and<jats:italic>Neocallichirus kenyaensis</jats:italic>sp. nov., are here proposed.</jats:p>

Kangtia, Pawana; Dahms, Hans-Uwe; Song, Sung Joon; Myoung, Jung-Goo; Khim, Jong Seong

doi: 10.1163/15685403-00003423pmid: N/A

<jats:p>All six naupliar stages of the harpacticoid copepod <jats:italic>Zaus wonchoelleei</jats:italic> Kangtia, Dahms, Song, Myoung, Park &amp; Khim, 2014 are described. A key for the identification of the naupliar stages is provided. Stages can be distinguished by number of segments of the exopod of antenna 2, setation of the limbs including the bud of the caudal ramus, and presence and setation of the bud of maxilla 1. In phylogenetic reconstructions there are several characters which link two taxa of different harpacticoid groups, the Harpacticidae of Exanechentera and the Thalestridae of Podogennonta. The Harpacticidae and the free-living genera of the Thalestridae develop from a 3-segmented naupliar antennular precursor in Harpacticidae and a 1-segmented antennule in Thalestridae to a 6-segmented antennule at copepodid I. Both families also share a single, stout spine terminally on the inner process of the mandibular naupliar endopodite which is unique for harpacticoid nauplii. A peculiar medial bifid seta on the antennal basis at nauplius I and II is also unique. This seta is replaced by a medial seta of the coxa at nauplius III, which has the same structure as the aforementioned set which gets reduced.</jats:p>

Han, Qingxi; Li, Xinzheng

doi: 10.1163/15685403-00003422pmid: N/A

<jats:p>The brown shrimp,<jats:italic>Crangon hakodatei</jats:italic>Rathbun, 1902, is a common species in northwestern Pacific waters. Based on an investigation of references since the 1950s, we studied the ecological features of this commercially important shrimp. The results show, that the species has a long reproductive period with ovigerous females throughout the year and two discrete peaks in the spawning season, i.e., in spring and in autumn. Its sex ratio also shows significant seasonal variation. This shrimp is a keystone species in the demersal trophic pathways in the northern Chinese seas. It occupies an intermediate position in the food web, acting both as an important food resource for flatfishes on a higher trophic level, and as a predator upon the early life stages of those flatfishes.</jats:p>

Izawa, Kunihiko

doi: 10.1163/15685403-00003419pmid: N/A

<jats:p>A series of descriptions of postembryonic developmental stages prior to the adult of<jats:italic>Hatschekia multibarbatae</jats:italic>Izawa, 2015 is presented based on free-living larvae reared from eggs detached from ovigerous females, as well as on copepodids I-V recovered together with adults from<jats:italic>Brotula multibarbata</jats:italic>Temminck &amp; Schlegel, 1846 (Pisces, Ophidiiformes, Ophidiidae). The number of naupliar stages preceding the infective copepodid I is three in this species. The postnaupliar development proceeds linearly, up to the adult.</jats:p>

Sakai, Katsushi; Türkay, Michael

doi: 10.1163/15685403-00003389pmid: N/A

Hendrickx, Michel E.

doi: 10.1163/15685403-00003428pmid: N/A

Daneliya, Mikhail

doi: 10.1163/15685403-00003421pmid: N/A