A new deep-water species of Myopiarolis Bruce, 2009 (Crustacea: Isopoda: Serolidae) from New Zealand waters

Myopiarolis tona sp. nov. is described from the Challenger Plateau, southern Lord Howe Rise and the west coast of the North Island, New Zealand at depths of 634–1250 m. M. tona sp. nov. can be identified by the prominent posteriorly directed dorsal nodule on fused pereonites 5–7. There are nine species in four genera of the cold-water, epibenthic family Serolidae recorded from New Zealand waters, three species of Myopiarolis Bruce, 2009, one undescribed species of Acutiserolis Brandt, 1988, four of Brucerolis Poore and Storey, 2009 and the monotypic Spinoserolis Brandt, 1988

Myopiarolis Bruce 2009

<i>Myopiarolis</i> Bruce, 2009 <p> <i>Myopiarolis</i> Bruce, 2009: 38.</p> <p> <i>Caecoserolis—</i> Poore and Brandt, 1997: 161 (part).</p> <p> Type species: <i>Myopiarolis systir</i> Bruce, 2009; by original designation.</p> <p> <b>Remarks</b>. The genus can be identified by the following combination of characters: small lenticular eyes (<5% head width) when present, coxae 2–4 distally truncate forming continuous body outline, broad but posteriorly produced coxa 6 that extend laterally along the pleotelson, pleonites 2 and 3 that curve posteriorly and run along the side of the pleotelson, but are laterally overlapped by coxa 6, antenna with slender peduncle articles 4 and 5 (4.6–6.3 and 8.6–10.3 times as long as wide, respectively). Compared to other serolid genera the uropods are short (<0.3 pleotelson), inserted ventrally about halfway along the pleotelson lateral margins, and the rami are consistently bluntly rounded. Females are similar to males, differing only in somatic ornamentation. Bruce (2009) listed the then known species of the genus together with a key to these species.</p>Published as part of <i>Spong, Keren & Bruce, Niel L., 2015, A new deep-water species of Myopiarolis Bruce, 2009 (Crustacea: Isopoda: Serolidae) from New Zealand waters, pp. 257-264 in Zootaxa 4057 (2)</i> on page 258, DOI: 10.11646/zootaxa.4057.2.6, <a href="http://zenodo.org/record/235341">http://zenodo.org/record/235341</a&gt

Myopiarolis tona Spong & Bruce, 2015, sp. nov.

<i>Myopiarolis tona</i> sp. nov. <p>(Figures 1–4)</p> <p> <b>Material examined.</b> <i>Holotype</i>: ♂ (8.0 mm), Challenger Plateau, off the West coast, South Island, New Zealand, 40.83o S, 168.24o E, 17 April 1980, depth 1009 m, stn P927 (NIWA 99811).</p> <p> <i>Paratypes</i>: 2 ♂ (8.5 [dissected and drawn], 8.0 mm). 2 ♀ (ovig. 10 [dissected allotype], 8.5 mm), same data as holotype (NIWA 32396). 1 ♀ (non-ovigerous 9.0 mm), North West Slope, off West coast, North Island, New Zealand, 38o S, 173.31o E, 14 March 1968, depth 1247–1250 m, stn E90–TAM (NIWA 32414).</p> <p> <i>Other material</i>: 1 ♂ (7.7 mm), South Lord Howe Rise, 36.92067o S, 167.5268o E, 30 May 2007, depth 1216 m, stn TAN0707/52 (NIWA 31571). 1 ♂ (7.5 mm), Challenger Plateau, 39.54367o S, 169.7145o E, 4 June 2007, depth 634 m, stn TAN0707/93 (NIWA 31574).</p> <p> <b>Description of male.</b> <i>Body</i> 1.3 times as long as wide, widest at pereonite 2, dorsal surfaces sparsely punctate. <i>Head</i> anterolateral lobes weakly convex; dorsally without tubercles, posterior margin with low rounded median tubercle and pair of low lateral tubercles. <i>Eye</i> minute (less than 5% greatest width of head), elliptical (lenticular/ ovoid), ommatidia not distinct. <i>Pereonites,</i> pereonite 1 anterolateral margin continuously convex; dorsal surfaces with medial posterially directed prominent blunt tubercle on fused pereonites 5–7; small median tubercles on pereonites 2–4, and pleonite 1 and 2; posterolateral margins of pereonite 1 with row of small tubercules; pereonites 3 and 4 with single small tubercule at posterodistal corner. <i>Coxae</i>, distal margins weakly convex; coxa 4 not posteriorly extended; coxa 5 extending posteriorly along 0.3 of pleotelson length; coxa 6 extending to insertion of uropod, and along 0.8 of pleotelson length. <i>Ventral coxal plate</i> s 2–4 meeting midline, mesially elevated, plates 2–4 mesially with ridges forming X-shape, 5 and 6 incompletely separate, 7 separate; sternites 5–7 visible, fused.</p> <p> <i>Pleonites</i> extending posteriorly along 0.8 of pleotelson lateral margin; pleonite 1 sternal plate with weak median ridge. <i>Pleotelson</i> 1.0 times as long as anterior width; dorsal surface with low median longitudinal carina; lateral carinae entirely carinate, pleotelson lateral margins convex, posterior margin converging to rounded caudomedial point, without distinct median excision.</p> <p> <i>Antennula</i> peduncle article 2 1.8 times as long as wide; articles 3 and 4 2.6 times as long as article 2; article 3 7.8 times as long as wide; flagellum 2.8 times as long as peduncle articles 3 and 4, with 39 articles, extending to pereonite 4. <i>Antenna</i> peduncle article 4 5.8 times as long as wide, 2.9 times as long as article 3; article 5 1.1 times as long as article 4, 9 times as long as wide; antennal flagellum 1.5 times as long as peduncle article 5, with 16 articles, extending to posterior of pereonite 3 or posterior of pereonite 4.</p> <p> <i>Epistome</i> with obtuse median point and median ventral projection. <i>Mandible incisor</i> even, without cusps. <i>Left mandible lacinia mobilis</i> 0.8 times as wide as incisor; palp article 2 with 20 distolateral biserrate setae, article 3 with 21 distolateral biserrate setae. <i>Maxilla</i> mesial lobe with 11 long, finely serrate setae; middle lobe with 2 long simple setae (terminal); lateral lobe with 2 distal simple setae. <i>Maxilliped palp</i> article 2 proximomesial margin with 6 setae, distomesial margin with 9 setae, lateral margin distally with 5 setae (continuously along margin); article 3 lateral margin with 3 setae, distal margin with 13 setae; endite distal margin RS simple.</p> <p> <i>Pereopod 1</i> propodus 2.2 times as long as wide, inferior margin with 48 robust setae; 24 wide RS finely pilose, 24 narrow RS distally bifid, with simple flagellum; dactylus with acute unguis. <i>Pereopod 2</i> basis 4.8 times as long as greatest width; ischium 0.6 times as long as basis, ischium 3.1 times as long as wide; merus 0.5 times as long as ischium, merus 1.8 times as long as greatest width, inferior margin with 1 distal cluster of 4 setae, superior distal angle with 4 setae; carpus 0.6 times as long as ischium, 2.6 times as long as wide, inferior margin with 3 clusters of setae; propodus 0.6 times as long as ischium, 2.5 times as long as wide, inferior margin with distinct heel, palm weakly concave, inferolateral margin with 4 RS, inferomesial margin with 3 RS, inferior margin RS distally bifid, distally pilose, distal margin with 10 setae; dactylus 0.8 times as long as propodus, unguis blunt, with prominent secondary unguis. <i>Pereopod 6</i> basis 4 times as long as greatest width; ischium 0.7 times as long as basis, ischium 3.5 times as long as wide, inferior margin with 1 cluster of setae, superior distal angle with 2 RS; merus 0.5 times as long as ischium, 2.2 times as long as wide, inferior margin with 4 clusters of setae, superior distal angle with 2 setae; carpus 0.8 times as long as ischium, 4.5 times as long as wide, inferior margin with 7 clusters of setae, superior distal angle with 7 setae; propodus 0.8 times as long as ischium, 7.6 times as long as wide, inferior margin with 7 clusters of setae, distal margin with 9 setae, inferior distal angle with 1 RS; dactylus 8 times as long as proximal width. <i>Pereopod 7</i> similar to, but 0.8 times as long as pereopod 6. Setae on inferior margins of pereopods 4–7 finely plumose. Inferior margins of pereopods 2–7 setulose fringe weakly developed.</p> <p> <i>Penial openings</i> adjacent, penes opening flush with surface of sternite 7.</p> <p> <i>Pleopod 1</i> peduncle 1.9 times as long as wide, mesial margin with 3 coupling setae; exopod 1.7 times as long as wide, with 34 PMS; endopod 2.6 times as long as wide, 0.6 times as long as exopod, with 18 PMS. <i>Pleopod 2</i> peduncle 1.2 times as long as wide, mesial margin with 2 coupling setae; exopod 1.7 times as long as wide, with 36 PMS; endopod 2.8 times as long as greatest width, lamellar part 3.1 times as long as wide, with 15 PMS; appendix masculina 4.1 times as long as endopod. <i>Pleopod 3</i> exopod with 37 PMS, endopod with 23 PMS. <i>Pleopod 4</i> exopod with complete transverse suture, endopod with complete transverse suture. <i>Pleopod 5</i> exopod with complete transverse suture, endopod with complete transverse suture.</p> <p> <i>Uropods</i> (rami + peduncle) 0.3 times as long as pleotelson, peduncle 0.8 times as long as endopod. <i>Endopod</i> 2.1 times as long as wide; distally broadly rounded. <i>Exopod</i> as long as endopod, 3 times as long as wide, distally broadly rounded.</p> <p> <b>Female.</b> Similar to the male; ridges on ventral coxal plate 4 less raised than in males, no ridges on 5. Pereopods 1 and 2 similar to male pereopod 3. No sexual dimorphism of pereopod 7 or pleopod 3.</p> <p> <b>Size</b>. Length: Males 7.5–8.5 mm (n= 5); females 9.0–10.0 mm (n=3).</p> <p> <b>Variation.</b> The large triangular median nodule on fused pereonites 5-7 is always prominent, but varies in height and shape, with some being more ‘hooked’ than others.</p> <p> <b>Remarks.</b> <i>Myopiarolis tona</i> <b>sp. nov.</b> can best be recognized by the head posterior margin with low rounded median tubercle and pair of lateral tubercles, small, low median tubercles present on pereonites 2–4 and 6, the large triangular median nodule on fused pereonites 5–7, and the coxae of pereonite 6 extend posteriorly to the insertion of the uropods. <i>Myopiarolis tona</i> <b>sp. nov.</b> is the only species of the genus with this ‘fin-shaped’ nodule. <i>Myopiarolis tona</i> is similar to <i>M. koro</i> Bruce, 2009, <i>M. lippa</i> Bruce, 2009, and <i>M. novacaledoniae</i> (Poore and Brandt, 1997) in outline and pleotelson features, while the nodules on the posterior margin of the head are similar to <i>M. norfanz</i> Bruce, 2009. In profile <i>M. tona</i> <b>sp. nov.</b> is most similar to <i>M. carinata</i>.</p> <p> <b>Distribution.</b> Off western New Zealand: South Lord Howe Rise (634 m), Challenger Plateau (1009–1216 m) and off northwestern New Plymouth (1248 m).</p> <p> <b>Etymology.</b> From the Maori word for nodule, referring to the prominent, posterior facing nodule on fused pereonites 5–7; noun in apposition.</p>Published as part of <i>Spong, Keren & Bruce, Niel L., 2015, A new deep-water species of Myopiarolis Bruce, 2009 (Crustacea: Isopoda: Serolidae) from New Zealand waters, pp. 257-264 in Zootaxa 4057 (2)</i> on pages 258-263, DOI: 10.11646/zootaxa.4057.2.6, <a href="http://zenodo.org/record/235341">http://zenodo.org/record/235341</a&gt

A new species of sponge-dwelling amphipod, Polycheria spongoteras sp. nov., from Spirits Bay, Northland, New Zealand

Peart, Rachael A., Spong, Keren, Sutherland, Judy, Kelly, Michelle (2019): A new species of sponge-dwelling amphipod, Polycheria spongoteras sp. nov., from Spirits Bay, Northland, New Zealand. Zootaxa 4674 (1): 127-141, DOI: https://doi.org/10.11646/zootaxa.4674.1.

Polycheria Haswell 1879

Genus Polycheria Haswell, 1879 Type species. Polycheria tenuipes Haswell, 1879 , by original designation. Diagnosis. Pereon broad, pleon compressed, to some extent carinate. Antennae sub-equal; A1 accessory flagellum absent. Mandibles without palp. Maxillipeds with well-developed palp. Gnathopods small, subchelate. Pereopods all prehensile, with narrow bases. Uropods biramous with rami equal in size. Telson cleft. (After Haswell 1879)Published as part of Peart, Rachael A., Spong, Keren, Sutherland, Judy & Kelly, Michelle, 2019, A new species of sponge-dwelling amphipod, Polycheria spongoteras sp. nov., from Spirits Bay, Northland, New Zealand, pp. 127-141 in Zootaxa 4674 (1) on page 129, DOI: 10.11646/zootaxa.4674.1.7, http://zenodo.org/record/345847

Mechanisms explaining nursery habitat association: how do juvenile snapper (Chrysophrys auratus) benefit from their nursery habitat?

Nursery habitats provide elevated survival and growth to the organisms that associate with them, and as such are a crucial early life-stage component for many fishes and invertebrates. The exact mechanisms by which these benefits are afforded to associated organisms, however, are often unclear. Here we assessed potential explanations of the nursery function of structurally complex habitats for post-settlement snapper, Chrysophrys auratus, in New Zealand. Specifically, we deployed Artificial Seagrass Units (ASUs) and used a combination of video observation, netting and diet analysis of associated post-settlement snapper as well describing potential prey within the micro-habitats surrounding ASUs. We did not observe any predation attempts and few potential predators, suggesting that for snapper the nursery value of structurally complex habitats is not as a predation refuge. The diet of post-settlement snapper mostly consisted of calanoid and cyclopoid copepods, which were most commonly sampled from within the water column. Nearly all suspected feeding events were also observed within the water column. When considering the velocity of water flow at each ASU, plankton sampling revealed a greater availability of copepods with increasing current strength, while netting and video observation demonstrated that the abundance of snapper was highest at sites with intermediate water velocity. This study highlights that the interaction between water flow and food availability may represent an important trade-off between energy expenditure and food intake for post-settlement snapper. Structurally complex habitats may mediate this relationship, allowing snapper to access sites with higher food availability while reducing swimming costs. This mechanism may have broader relevance, potentially explaining the importance of estuarine nursery habitats for other species

Map of Whangarei Harbour.

<p>Intertidal areas and the location of sampling sites indicated by light grey shading and starts respectively. New Zealand and the location of Whangarei Harbour within east-northland inset.</p

Abundance of invertebrates collected from all sites via four different sampling methods.

<p>Abundances are standardised by the most abundant taxa within a sampling method, but all plots are presented in order of abundance for diet invertebrates. Taxonomic nomenclature presented is not always at same level.</p

Abundance, condition, pelagic feeding frequency and location of post-settlement snapper by site as observed from video deployments and ‘brush and dustpan’ netting in Whangarei Harbour.

<p>(A) Abundance: proportion of two minute video segments where post-settlement snapper were observed. (B) Abundance: number of snapper captured by ‘brush and dustpan’. Kruskal Wallis test did not find any significant differences. (C) Fish condition: Condition of post-settlement snapper captured by ‘brush and dustpan’ netting. (D) Location: average proportion of observations of post-settlement snapper within each position category (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122137#sec002" target="_blank">methods</a> for category definitions). Statistical test conducted for observations that were categorised as near seagrass. (E) Feeding events: proportion of two minute video segments where post-settlement snapper were present that suspected pelagic feeding events were observed (standardised for snapper abundance). For all plots sites are listed in increasing order of maximum water velocity (from Whangarei Harbour hydrodynamic model), values at each site are averages from four replicate ASUs ±1 standard error. Different lowercase letters denote significant differences between sites at the α = 0.05 level (Student-Newman-Keuls tests).</p