A new species of Orchomenella (Amphipoda, Tryphosidae) described from hydrothermal vent in the Okinawa Trough, Northwest Pacific

A new species of the family Tryphosidae, Orchomenella compressa sp. nov., is described from hydrothermal vents in the Okinawa Trough. This is the first known Orchomenella species found in vent fields. Important morphological characters that differentiate O. compressa sp. nov. from its congeners are the absence of eyes, the compressed distal three articles of gnathopod 2, the shape of the posterior margin of epimerons 2 and 3, and the number of dorsal spines on the telson. The genetic divergence of the analyzed COI gene clearly supports this new taxon

Litarcturus Brandt 1990

Genus <i>Litarcturus</i> Brandt, 1990 <p> <i>Litarcturus</i> Brandt, 1990: 88 –89; Poore, 2001: 224; Poore, 2015: 14.</p>Published as part of <i>Liu, Wenliang & Sha, Zhongli, 2015, Litarcturus kexueiae sp. nov., a new deep-sea isopod from the Okinawa Trough (Crustacea, Isopoda, Valvifera, Antarcturidae), pp. 531-540 in Zootaxa 4013 (4)</i> on page 531, DOI: 10.11646/zootaxa.4013.4.4, <a href="http://zenodo.org/record/236981">http://zenodo.org/record/236981</a&gt

Litarcturus kexueiae sp. nov., a new deep-sea isopod from the Okinawa Trough (Crustacea, Isopoda, Valvifera, Antarcturidae)

Liu, Wenliang, Sha, Zhongli (2015): Litarcturus kexueiae sp. nov., a new deep-sea isopod from the Okinawa Trough (Crustacea, Isopoda, Valvifera, Antarcturidae). Zootaxa 4013 (4): 531-540, DOI: http://dx.doi.org/10.11646/zootaxa.4013.4.

Litarcturus kexueiae Liu & Sha, 2015, sp. nov.

<i>Litarcturus kexueiae</i> sp. nov. <p>Figs 1–5</p> <p> <b>Material examined.</b> Holotype, adult male (total length, 13.8 mm, without antennae), MBM 240861, Okinawa Trough (27°40.300´N; 126°54.174´E), RY0231, depth 2115 m, bottom sandy mud, coll. Zhongli Sha, by Agassiz trawl, 23 April 2014.</p> <p> <b>Description.</b> Body (Fig. 1 A–B) length 13.8 mm. Eyes rounded, large and protruding, 0.36 of lateral length of cephalothorax. Body long, slender, pereonite 1 fused with head; dorsal transverse ridge between cephalothorax and pereonite 1. Preocular spines absent; supraocular spines long, slender and directed anteriorly, unarmed, not covering the eyes in dorsal view, about 3.0 times as long as diameter of eye. Further dorsal spines are lacking. All pereonites unarmed, with rough cuticle. Pereonites 1–3 of about same length and width; pereonite 4 longest, slightly narrower than pereonites 1–3, of about the same width as pereonites 6–7; pereonite 5 slightly longer than pereonites 4 and 6–7. Tergites of pereonites 5–7 with concave posterior border into which the following segment fits when the animal bends dorsally.</p> <p>All pleonites fused with pleotelson, unarmed. Pleotelson length about 0.25 times body length, width about 0.5 of total pleotelson length, partly with small scattered tubercles. Posterolateral pleotelsonic spines strong and straight, unarmed, at 0.62 of pleotelson length, about 0.6 times as long as caudal part of pleotelson. Pleotelson apex prominent, triangular and caudally rounded.</p> <p>Antennula (Fig. 3 A): length 0.18 times body length, with 2 flagellar articles; peduncular article 1 broadest, 1.4 times longer than wide and shorter than second one, unarmed; article 2 longest, 1.2 times as long as article 1, unarmed; article 3 slightly shorter than article 2, unarmed; flagellar article 1 a very short ring with 1 lateral slender bristle; article 2 2.6 times as long as peduncular article 3, with 8 groups of 2 aesthetascs accompanied by several simple setae, apically 2 terminal simple setae and another 2 aesthetascs.</p> <p>Antenna (Fig. 3 B): peduncle length 0.9 times body length; article 2 short, 0.3 length of article 3, with 2 parallel rows of short setae; articles 3 and 4 with 2 parallel rows of setae, arranged in groups of 1 long and 1 shorter setae; article 5 long and slender, with a row of short setae, arranged in groups of 1 long and 1 shorter setae; flagellum broken, article 1 with 2 parallel rows of short setae.</p> <p>Mouthparts typical of the family (Fig. 2 A–C).</p> <p>Maxilliped (Fig. 2 D) with a long oval-shaped epipod, strong endite and five-segmented palp. Epipodite covered with fine setae laterally and medially. Endite as long as epipodite, surpassing the middle of the second palp article, distal margin covered with fine setae and 7 robust setulate setae, distolaterally with 3 short plumose setae.</p> <p>Palp article 1 shortest, length 0.7 times length of second article, with few short simple setae on ventral margin and ventrolateral surface; palpal article 2 with short simple setae on ventral margin and ventrolateral surface; article 3 longest, 1.9 times longer than article 2, with dense simple and pectinate setae on ventral margin and ventrolateral surface and 2 long pectinate setae dorsodistally; article 4 about 1.5 times as long as article 2, with dense simple and pectinate setae on ventral margin and ventrolateral surface and 4 long pectinate setae dorsodistally; article 5 1.4 times longer than article 1, with long simple and pectinate setae apically.</p> <p>Pereopod 1 (Fig. 3 C) more robust than pereopods 2–7; basis longer than propodus, 2.1 times longer than wide, distoventrally with several long and slender simple setae, dorsal surface equipped with row of setules; ischium 0.9 times basis length, 1.7 times longer than wide, ventrally with dense long simple setae on distal half; merus 0.5 times ischium length, 1.8 times wider than long, with dense long simple setae ventrally and 2 anterodistal setae, carpus trapezoidal, 1.6 times wider than long, about as long as merus, with dense long simple setae ventrally; propodus subchelate and slender, 2.2 times carpus length, twice as long as wide; ventrally and partly laterally with dense long slender simple setae, dorsolateral surface with dense pectinate setae; dactylus shorter than propodus, 3.3 times longer than wide, with a unguis and a secondary unguis, and between bearing a seta, with several long and slender simple setae.</p> <p>Pereopods 2–4 similar, with long setae on posteromedial margins, without spines on anterolateral margins; long filter setae present on ischium, merus, carpus and propodus but lacking on dactylus (unknown in pereopod 3). Pereopod 2 (Fig. 3 D) basis 1.8 times longer than wide, dorsally unarmed, distoventrally with several long and slender simple setae; ischium length 0.7 times basis length, 1.4 times longer than wide, dorsally unarmed, ventrally with 2 parallel rows of setae, every row with 6 groups of setae and arranged in groups of 1 long filtering seta and 1 shorter simple seta; merus 1.5 times ischium length, 1.8 times longer than wide, with 1 small simple seta distodorsally, ventrally with 2 parallel rows of setae, every row with 6 groups of setae and arranged in groups of 1 long filtering seta and 1 shorter simple seta; carpus 2.2 times merus length, 6.8 times longer than wide, with several small simple setae dorsally, ventrally with 2 parallel rows of setae, every row with 16 groups of setae and arranged in groups of 1 long filtering seta and 1 shorter simple seta; propodus almost as long as carpus, 9.8 times longer than wide, with 2 moderate setae and 3 small simple setae dorsally, ventrally with 2 parallel rows of setae, every row with 14 groups of setae and arranged in groups of 1 long filtering seta and 1 shorter simple seta; dactylus 0.5 times propodus length, 11.1 times longer than wide, with 4 small simple setae dorsally, 2 small simple setae ventrally; unguis 0.5 times dactylus length, with a short ventral claw and a medial seta.</p> <p>Pereopod 3 (Fig. 4 A) basis 2.8 times longer than wide, dorsally unarmed, distoventrally with several long and slender simple setae; ischium 0.6 times basis length, 1.6 times longer than wide, dorsally unarmed, ventrally with 2 parallel rows of setae, every row with 7 groups setae and arranged in groups of 1 long filtering and 1 shorter simple seta; merus 1.5 times ischium length, 2.1 times longer than wide, dorsally unarmed, ventrally with 2 parallel rows of setae, every row with 7 groups setae and arranged in groups of 1 long filtering and 1 shorter simple seta; carpus 2.3 times merus length, 6.5 times longer than wide, with several small simple setae dorsally, ventrally with 2 parallel rows of setae, every row with 15 groups of setae and arranged in groups of 1 long filtering and 1 shorter simple seta; propodus broken off.</p> <p>Pereopod 4 (Fig. 4 B) basis 3.6 times longer than wide, dorsal margin with a big triangular tooth and scattered with several small tubercles, distoventrally with several long and slender simple setae; ischium 0.6 times basis length, 2.6 times longer than wide, dorsally unarmed, ventrally with 2 parallel rows of setae, every row with 7 groups of setae and arranged in groups of 1 long filtering and 1 shorter simple seta; merus almost as long as ischium, 2.3 times longer than wide; with 1 small simple seta distodorsally, ventrally with 2 parallel rows of setae, every row with 7 groups of setae and arranged in groups of 1 long filtering and 1 shorter simple seta; carpus 2.0 times merus length, 5.0 times longer than wide, with several small simple setae dorsally, ventrally with 2 parallel rows of setae, every row with 12 groups of setae and arranged in groups of 1 long filtering and 1 shorter simple seta; propodus about 0.9 times carpus length, 7.8 times longer than wide, with 2 moderate setae and 3 small simple setae dorsally, ventrally with 2 parallel rows of setae, every row with 11 groups of setae and arranged in groups of 1 long filtering and 1 shorter simple seta; dactylus 0.6 times propodus length, 10.0 times longer than wide, with 4 small simple setae dorsally and ventrally; unguis 1/3 times dactylus length, with a short ventral claw and a medial seta.</p> <p>Pereopod 5 (Fig. 4 C) broken off, only basis remains, 3.4 times longer than wide, with 3 feather-like setae dorsally, dorsal and ventral surface covered with extremely dense mat of fine setae.</p> <p>Pereopods 6–7 (Figs. 4 D–E) shorter and stronger than pereopods 2–4; two distal claws, stouter and much shorter than unguis of pereopods 2, 4. Pereopod 6 (Fig. 4 D) basis longest article, 3.7 times longer than wide, with 3 feather-like setae dorsally, dorsal and ventral surface covered with extremely dense mat of fine setae; ischium 0.6 times basis length, 2.3 times longer than wide, with few simple setae ventrally, dorsal and ventral surface covered with extremely dense mat of fine setae; merus 0.6 times ischium length, 1.4 times longer than wide, dorsal and ventral surface covered with extremely dense mat of fine setae, ventral surface with 2 row of short spines, each row arranged in 4 spines; carpus 0.9 times length merus, 0.8 times longer than wide, dorsal and ventral surface covered with few setules, ventral surface with 2 row of short spines, each row arranged in 4 spines; propodus 2.6 times longer than carpus, 3.3 times longer than wide, dorsal surface covered with few fine setae, ventral surface with 1 row of 7 short spines; dactylus 0.9 times propodus length, 5.0 times longer than wide, with few simple setae and several setules dorsally and ventrally; one simple seta and unguis, secondary unguis distally.</p> <p>Pereopod 7 (Fig. 4 E) basis longest article, 2.8 times longer than wide, with 3 feather-like setae dorsally, dorsal and ventral surface covered with extremely dense mat of fine setae; ischium 0.6 times basis length, 1.6 times longer than wide, with few simple setae ventrally, dorsal and ventral surface covered with extremely dense mat of setules; merus 0.8 times ischium length, 0.6 times longer than wide, dorsal and ventral surface covered with extremely dense mat of fine setae, ventral surface with 2 row of short spines, each row arranged in 4 spines; carpus 0.9 times longer than merus, 1.6 times longer than wide, dorsal and ventral surface covered with extremely dense mat of fine setae, ventral surface with 2 row of short spines, each row arranged in 4 spines; propodus 2.7 times longer than carpus, 3.6 times longer than wide, dorsal surface covered with few setules, ventral surface with 1 row of 6 short spines; dactylus 0.8 times propodus length, 4.7 times longer than wide, with few simple setae and several setules dorsally and ventrally, one simple seta and unguis, secondary unguis distally.</p> <p>Penial plate elongate (Fig. 5 B), tapering proximally and distally, unarmed.</p> <p>Pleopod 1 (Fig. 5 C) peduncle with 11 small triangular spine-like robust setae in a row laterally, ventromedially with seven coupling setae with hooked tips; exopod 1.1 times longer than endopod, 3.4 times as long as wide, laterally and apically with long plumose setae, posterior surface with transverse groove, ending with a protrusion on distal half of lateral margin; endopod with long plumose setae laterally and apically.</p> <p>Pleopod 2 (Fig. 5 D) exopod about as long as endopod, with long plumose setae laterally and apically; endopod of about same width as exopod, with long plumose setae laterally and apically; stiletto-like appendix masculina 1.1 times as long as endopod, with acute apex.</p> <p>Pleopod 3 (Fig. 5 E) exopod 1.2 times longer than endopod, setae absent; endopod of about same width as exopod, with a long and slender setae distolaterally.</p> <p>Pleopod 4 (Fig. 5 F) exopod 1.1 times longer than endopod, setae absent; endopod of about same width as exopod, with few simple setae laterally and 4 long and slender setae distolaterally.</p> <p>Pleopod 5 (Fig. 5 G) exopod 1.1 times longer than endopod, setae absent; endopod of about same width as exopod, with few simple setae laterally and 4 long and slender plumose setae distolaterally.</p> <p>Uropod (Fig. 5 A) biramous, peduncle with 14 long plumose setae on distolateral margin and a small triangular spine distally, surface laterally unarmed; exopod broader than linear endopod, about 1.3 times as long as endopod, unarmed distally; endopod with 3 simple setae distally.</p> <p> <b>Etymology.</b> The species name is derived from the oceanographic vessel “ <i>Kexue”</i> of Institute of Oceanology, Chinese Academy of Sciences, which contributed substantially to biological studies of Okinawa Trough.</p> <p> <b>Distribution and habitat.</b> Only known from type locality (Okinawa Trough, East China Sea, 2115 m).</p> <p> <b>Remarks.</b> The present new species is assigned to <i>Litarcturus</i> because of the following characters: with the tendency to reduce cuticular spines on the whole body surface; cephalothorax with one pair of supraocular spines, in some cases reduced or very small; caudal pleotelsonic spines comparatively short.</p> <p> <i>Litarcturus kexueiae</i> <b>sp. nov.</b> belongs to the third group with <i>L. granulosus</i> (Nordenstam, 1933) and <i>L. stebbingi</i> (Beddard, 1886), with supraocular and caudal pleotelsonic spines. However, <i>L. kexueiae</i> <b>sp. nov.</b> differs markedly from <i>L. granulosus</i> as its supraocular spines are longer than the cephalothorax apex (versus supraocular spines not longer than the cephalothorax apex), and from <i>L. stebbingi</i> as its caudal pleotelsonic spines are longer than the pleotelson apex (versus caudal pleotelsonic spines not longer than the pleotelson apex).</p>Published as part of <i>Liu, Wenliang & Sha, Zhongli, 2015, Litarcturus kexueiae sp. nov., a new deep-sea isopod from the Okinawa Trough (Crustacea, Isopoda, Valvifera, Antarcturidae), pp. 531-540 in Zootaxa 4013 (4)</i> on pages 533-539, DOI: 10.11646/zootaxa.4013.4.4, <a href="http://zenodo.org/record/236981">http://zenodo.org/record/236981</a&gt

Litarcturus Brandt 1990

Key to the species of the genus <i>Litarcturus</i> Brandt, 1990 <p> 1. Pleotelson without caudal spines................................................... <i>L. bicornis</i> (Kensley, 1984)</p> <p>- Pleotelson with caudal spines............................................................................ 2</p> <p>2. Head without supraocular spines......................................................................... 3</p> <p>- Head with supraocular spines........................................................................... 6</p> <p> 3. Pereonites 1–7 with submedial spines............................................ <i>L. americanus</i> (Beddard, 1886)</p> <p>- Pereonites 1–7 without submedial spines.................................................................. 4</p> <p> 4. Pleotelson with caudal spines not surpassing apex........................................ <i>L. lillei</i> (Tattersall, 1921)</p> <p>- Pleotelson with caudal spines surpassing apex............................................................... 5</p> <p> 5. Head with supraocular lobe...................................................... <i>L. antarcticus</i> (Bouvier, 1910)</p> <p> - Head without supraocular lobe..................................................... <i>L. coppingeri</i> (Miers, 1881)</p> <p>6. Head with supraocular spines surpassing apex............................................................. 7</p> <p> - Head with supraocular spines not surpassing apex................................. <i>L. granulosus</i> (Nordenstam, 1933)</p> <p> 7. Pleotelson with caudal spines not surpassing apex..................................... <i>L. stebbingi</i> (Beddard, 1886)</p> <p> - Pleotelson with caudal spines surpassing apex............................................... <i>L. kexueiae</i> <b>sp. nov.</b></p>Published as part of <i>Liu, Wenliang & Sha, Zhongli, 2015, Litarcturus kexueiae sp. nov., a new deep-sea isopod from the Okinawa Trough (Crustacea, Isopoda, Valvifera, Antarcturidae), pp. 531-540 in Zootaxa 4013 (4)</i> on page 532, DOI: 10.11646/zootaxa.4013.4.4, <a href="http://zenodo.org/record/236981">http://zenodo.org/record/236981</a&gt

Divergence history and hydrothermal vent adaptation of decapod crustaceans: A mitogenomic perspective.

Decapod crustaceans, such as alvinocaridid shrimps, bythograeid crabs and galatheid squat lobsters are important fauna in the hydrothermal vents and have well adapted to hydrothermal vent environments. In this study, eighteen mitochondrial genomes (mitogenomes) of hydrothermal vent decapods were used to explore the evolutionary history and their adaptation to the hydrothermal vent habitats. BI and ML algorithms produced consistent phylogeny for Decapoda. The phylogenetic relationship revealed more evolved positions for all the hydrothermal vent groups, indicating they migrated from non-vent environments, instead of the remnants of ancient hydrothermal vent species, which support the extinction/repopulation hypothesis. The divergence time estimation on the Alvinocarididae, Bythograeidae and Galatheoidea nodes are located at 75.20, 56.44 and 47.41-50.43 Ma, respectively, which refers to the Late Cretaceous origin of alvinocaridid shrimps and the Early Tertiary origin of bythograeid crabs and galatheid squat lobsters. These origin stories are thought to associate with the global deep-water anoxic/dysoxic events. Total eleven positively selected sites were detected in the mitochondrial OXPHOS genes of three lineages of hydrothermal vent decapods, suggesting a link between hydrothermal vent adaption and OXPHOS molecular biology in decapods. This study adds to the understanding of the link between mitogenome evolution and ecological adaptation to hydrothermal vent habitats in decapods

First comprehensive analysis of lysine acetylation in Alvinocaris longirostris from the deep-sea hydrothermal vents

Abstract Background Deep-sea hydrothermal vents are unique chemoautotrophic ecosystems with harsh conditions. Alvinocaris longirostris is one of the dominant crustacean species inhabiting in these extreme environments. It is significant to clarify mechanisms in their adaptation to the vents. Lysine acetylation has been known to play critical roles in the regulation of many cellular processes. However, its function in A. longirostris and even marine invertebrates remains elusive. Our study is the first, to our knowledge, to comprehensively investigate lysine acetylome in A. longirostris. Results In total, 501 unique acetylation sites from 206 proteins were identified by combination of affinity enrichment and high-sensitive-massspectrometer. It was revealed that Arg, His and Lys occurred most frequently at the + 1 position downstream of the acetylation sites, which were all alkaline amino acids and positively charged. Functional analysis revealed that the protein acetylation was involved in diverse cellular processes, such as biosynthesis of amino acids, citrate cycle, fatty acid degradation and oxidative phosphorylation. Acetylated proteins were found enriched in mitochondrion and peroxisome, and many stress response related proteins were also discovered to be acetylated, like arginine kinases, heat shock protein 70, and hemocyanins. In the two hemocyanins, nine acetylation sites were identified, among which one acetylation site was unique in A. longirostris when compared with other shallow water shrimps. Further studies are warranted to verify its function. Conclusion The lysine acetylome of A. longirostris is investigated for the first time and brings new insights into the regulation function of the lysine acetylation. The results supply abundant resources for exploring the functions of acetylation in A. longirostris and other shrimps

Full-Length Transcriptome Comparison Provides Novel Insights into the Molecular Basis of Adaptation to Different Ecological Niches of the Deep-Sea Hydrothermal Vent in Alvinocaridid Shrimps

The deep-sea hydrothermal vent ecosystem is one of the extreme chemoautotrophic environments. Shinkaicaris leurokolos Kikuchi and Hashimoto, 2000, and Alvinocaris longirostris Kikuchi and Ohta, 1995, are typically co-distributed and closely related alvinocaridid shrimps in hydrothermal vent areas with different ecological niches, providing an excellent model for studying the adaptive evolution mechanism of animals in the extreme deep-sea hydrothermal vent environment. The shrimp S. leurokolos lives in close proximity to the chimney vent discharging high-temperature fluid, while A. longirostris inhabits the peripheral areas of hydrothermal vents. In this study, full-length transcriptomes of S. leurokolos and A. longirostris were generated using a combination of single-molecule real-time (SMRT) and Illumina RNA-seq technology. Expression analyses of the transcriptomes showed that among the top 30% of highly expressed genes of each species, more genes related to sulfide and heavy metal metabolism (sulfide: quinone oxidoreductase, SQR; persulfide dioxygenase, ETHE1; thiosulfate sulfurtransferase, TST, and ferritin, FRI) were specifically highly expressed in S. leurokolos, while genes involved in maintaining epibiotic bacteria or pathogen resistance (beta-1,3-glucan-binding protein, BGBP; endochitinase, CHIT; acidic mammalian chitinase, CHIA, and anti-lipopolysaccharide factors, ALPS) were highly expressed in A. longirostris. Gene family expansion analysis revealed that genes related to anti-oxidant metabolism (cytosolic manganese superoxide dismutase, SODM; glutathione S-transferase, GST, and glutathione peroxidase, GPX) and heat stress (heat shock cognate 70 kDa protein, HSP70 and heat shock 70 kDa protein cognate 4, HSP7D) underwent significant expansion in S. leurokolos, while CHIA and CHIT involved in pathogen resistance significantly expanded in A. longirostris. Finally, 66 positively selected genes (PSGs) were identified in the vent shrimp S. leurokolos. Most of the PSGs were involved in DNA repair, antioxidation, immune defense, and heat stress response, suggesting their function in the adaptive evolution of species inhabiting the extreme vent microhabitat. This study provides abundant genetic resources for deep-sea invertebrates, and is expected to lay the foundation for deep decipherment of the adaptive evolution mechanism of shrimps in a deep-sea chemosynthetic ecosystem based on further whole-genome comparison

Supplementary material 1 from: Mei Z, Sha Z, Sun S (2023) Going deeper and further: a range and depth extension for the deep-sea feather star Paratelecrinus cubensis (Carpenter, 1881) (Comatulida, Atelecrinidae), first record from the Western Pacific. ZooKeys 1184: 103-113. https://doi.org/10.3897/zookeys.1184.110577

Sequence information needed to construct phylogenetic tree