Seasonal modulation of mesoscale processes alters nutrient availability and plankton communities in the Red Sea

Hydrographic and atmospheric forcing set fundamental constraints on the biogeochemistry of aquatic ecosystems and manifest in the patterns of nutrient availability and recycling, species composition of communities, trophic dynamics, and ecosystem metabolism. In the Red Sea, latitudinal gradients in environmental conditions and primary production have been ascribed to fluctuations in Gulf of Aden Water inflow, upwelling/mixing, and regenerated nutrient utilization i.e. rapidly recycled nitrogen in upper layers. However, our understanding of upper layer dynamics and related changes in plankton communities, metabolism and carbon and nitrogen export is limited. We surmised that stratification and mesoscale eddies modulate the nutrient availability and taxonomic identity of plankton communities in the Red Sea. Based on remote-sensing data of sea level anomalies and high resolution in situ measurements (ScanFish) we selected stations for hydrographic CTD profiles, water sampling (nutrients, seawater oxygen stable isotopes [δ18OSW]), phytoplankton and zooplankton collections. In fall 2014, strong stratification subjected the plankton community to an overall nitrogen and phosphorus shortage. The nutrient deficiency increased numbers of heterotrophic dinoflagellates, microzooplankton, and diazotrophs (Trichodesmium, diatom-diazotroph associations [DDAs]), albeit largely decreased phytoplankton and mesozooplankton abundances. In spring 2015, mesoscale eddies increased the nutrient availability, and the thermohaline characteristics and low δ18OSW point to the interaction of eddies with Gulf of Aden Surface Water (GASW). Cyclonic eddies and, most likely, the availability of nutrients associated with the GASW, increased the abundances of autotrophs (diatoms, Prasinophytes) and supported larger numbers of zooplankton and their larvae. We demonstrate that the interplay of stratification, advection of Gulf of Aden water and mesoscale eddies are key elements to better understand changes in plankton community composition, ecosystem metabolism, and macronutrient export in the Red Sea in space and time

First record and redescription of Macandrewella cochinensis Gopalakrishnan, 1973 (Copepoda, Scolecitrichidae) from the Red Sea, with notes on swarm formation

During a study of the epipelagic zooplankton carried out near the fringing reef around Sharm El-Sheikh area, in the northern Red Sea, female and male specimens of the poorly known calanoid copepod Macandrewella cochinensis Gopalakrishnan, 1973 were collected. This is the first record of species occurrence in the Red Sea. Macandrewella cochinensis was previously known only from the offshore water of Cochin, south west of India. The Red Sea specimens are described in details herein to allow their comparison with the specimens from the type locality, because original description of M. cochinensis is incomplete and causes some taxonomic confusion. The most important characters that may have been overlooked in the original description are: shape of projections of the female distolateral prosomal borders, details of morphology of the asymmetrical female genital double-somite and presence of leg 5 in female

First report of the presence of Acartia bispinosa Carl, 1907 (Copepoda, Calanoida) in a semi-enclosed Bay (Sharm El-Maya), northern Red Sea with some notes on its seasonal variation in abundance and body size

The calanoid copepod, Acartia bispinosa Carl, 1907, is reported for the first time in the Red Sea, where it is found to be an important copepod in the mesozooplankton community structure of the Sharm El-Maya Bay. Female and male are fully redescribed and illustrated of as the mouthparts of this species have never previously been described and figured. Acartia bispinosa was collected in the plankton samples throughout the year and showed two peaks of abundance, a pronounced one in April (4234 individuals m-3), and second smaller peak during November (1784 individuals m-3). The average total length of females varied between 1.32 and 1.53 mm at the end of June and January respectively. For males, the average total length fluctuated between 1.07 and 1.16 mm at end of June and March respectively. Temperature showed an inverse relationship with the body length (P > 0.001) and seemed to be one of the prime factors affecting the body length of both sexes

First report of the presence of Acartia bispinosa Carl, 1907 (Copepoda, Calanoida) in a semi-enclosed Bay (Sharm El-Maya), northern Red Sea with some notes on its seasonal variation in abundance and body size

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A new species of Centropages (Copepoda: Calanoida: Centropagidae) from the central Red Sea based on morphological and molecular evidence

El-Sherbiny, Mohsen M., Al-Aidaroos, Ali M. (2015): A new species of Centropages (Copepoda: Calanoida: Centropagidae) from the central Red Sea based on morphological and molecular evidence. Zootaxa 3911 (3): 396-410, DOI: http://dx.doi.org/10.11646/zootaxa.3911.3.

Centropages mohamedi El-Sherbiny & Al-Aidaroos, 2015, sp. nov.

<i>Centropages mohamedi</i> sp. nov. <p>(Figs 2,4–6)</p> <p> <b>Type material.</b> Holotype. Adult female, 1.39 mm, dissected and mounted on 1 glass slide with CMC-10 (Reg. No NHMUK 2014.613-622) collected at coastal water off Obhur Creek, Jeddah, central Red Sea, (21° 41.398' N, 39° 3.002' E) on 31 May 2012, 0.5 m depth.</p> <p>Allotype. Adult male, 1.20 mm, partly dissected and mounted in 1 glass slide with CMC-10 (Reg. No NHMUK 2014.623-632) collected at coastal water off Obhur Creek, Jeddah, central Red Sea (21° 41.398' N, 39° 3.002' E), on 31 May 2012, 0.5 m depth.</p> <p>Additional paratypes. 20 adult females (body length: 1.31–1.45 mm, mean ± SD = 1.36 ± 0.06 mm) and 17 adult males (body length: 1.18–1.35 mm, mean ± SD = 1.26 ± 0.07 mm) in 70% alcohol (Registration number: NHMUK 2014.613-622 and NHMUK 2014.623-632 respectively) collected at coastal water off Obhur Creek, Jeddah, central Red Sea (21° 41.398' N, 39° 3.002' E), on 31 May 2012, 0.5 m depth.</p> <p> <b>Description.</b> Female (holotype). Body (Fig. 2 A) robust, prosome plump comprising cephalosome and five pedigerous somites; prosome about 2.3 times as long as urosome; cephalosome distinctly separated from first pediger; fourth and fifth pedigerous somites separated; fifth pedigerous somite symmetrical with posterolateral corners slightly pointed in dorsal and lateral aspects (Fig. 2 A, B). Rostrum bearing long pair of frontal filaments directed postero-ventrally with broad base (Figs 2 C, 3A). Urosome (Figs 2 D–F, 3B) of 3 free somites; genital double somite symmetrical (Figs 3 B–C); genital receptacle located half way along ventral surface covered with blunt operculum. Second urosomite symmetrical, slightly shorter than genital double somite; anal somite symmetrical and shorter than preceding free abdominal somite. Caudal rami symmetrical and approximately 2.3 times as long as wide.</p> <p>Antennules (Fig. 2 G, H) symmetrical, 24-segmented, extending about to middle of anal somite. Armature formula as follows: (segment 1) = 2 setae + aesthetasc (ae), (2) = 2 setae + ae, (3) = 2 + ae, VI (4) = 2 + ae,(5) = 2 + ae, (6) = 1 + ae, (7) = 2 + ae, (8) = 2 (1 spiniform) + ae, (9) = 2 + ae, (10) = 2 + ae, (11) =1 + ae, (12) = 2 (1 spiniform) + ae, (13) = 1 + ae, (14) = 2 + ae, (15) = 2 + ae, (16) = 2 + ae, (17) = 2 + ae, (18) = 2 + ae, (19) = 2 + ae, (20) = 1 + ae, (21) = 1, (22) = 1 + 1, (23) = 1 + 1, (24) = 5+ae.</p> <p>Antenna (Fig. 4 A) biramous with short coxa bearing plumose seta at distomedial angle; basis with 2 subequal setae on distomedially; exopod indistinctly 7-segmented with setal formula of 1, 4, 1, 1, 1, 1, 3; endopod 2- segmented, proximal segment with 2 unequal subterminal setae; distal segment bilobed, with medial (proximal) lobe bearing 8 setae, and with lateral (distal) lobe crowned with 7 setae and transverse row of long spinules subdistally on lateral margin.</p> <p>Mandibular gnathobase (Fig. 4 B) with cutting edge carrying 8 teeth on coxal cutting edge and dorsal spinulose seta; ventralmost tooth largest, smooth and unicuspid, third to sixth teeth bicuspidate and third to seventh teeth ornamented with 2 rows of short spinules anterodistally at base. Palp (Fig. 4 C) basis with 4 unequal setae on medial margin; exopod 5-segmented with setal formula of 1, 1, 1, 1, 2; endopod 2-segmented, proximal segment with 4 setae at distomedial corner; distal segment with 8 unequal setae and subapical random patch of spinules row of fine spinules.</p> <p>Maxillule (Fig. 4 D) with praecoxal arthrite bearing 9 marginal strong spines plus four on posterior surface. Coxal epipodite with 9 setae; coxal endite with 3 spinulose setae; basal exite with 1 vestigial seta. Basis fused to exopod and endopod; proximal basal endite armed with 4 setae and on distal endite 7 setae. Exopod carrying 11 marginal setae; endopod indistinctly 2-segmented with 4 and 5 setae respectively.</p> <p>Maxilla (Fig. 4 E) indistinctly 7-segmented, containing partially coalesced praecoxa and coxa, basis and 2- segmented endopod. Praecoxal and coxal endites carrying 5, 3, 3 and 3 bilaterally spinulate setae respectively; basal endite with 4 setae, one longer than others; endopod 2-segmented, carrying 7 bilaterally spinulate setae.</p> <p>Maxilliped (Fig. 4 F) 8-segmented comprising syncoxa, basoendopod and free 6-segmented endopod (first endopodal segment almost completely incorporated into basis). Syncoxal lobes with 1, 2, 3, 4 setae on its medial margin, small patch of spinules on medial surface proximal to seta of first syncoxal lobe and other patch near the third lobe. Basis slightly shorter than syncoxa, with 3 setae (middle seta with proximal setule located in spiral pattern, Fig. 3 D), row of strong spinules and long hairs along medial margin of segment proximal to basal setae; endopod with setal formula of 2, 4, 4, 3, 3 + 1, 1+2+ 1.</p> <p>Swimming legs 1–4 (Fig. 5 A–D) with 3 segmented exopod; endopod 2-segmented in legs 1–3, and 3- segmented in legs 4–5. Leg 1 with medial basal seta reaching to end of proximal endopodal segment. Leg 5 (Fig. 5 E–H) symmetrical; second exopodal segment with strong medial process medially, slightly longer than segment itself with bilateral serration along distal half of lateral margin (Figs 5 F–G, 3E–F). Armature of legs as follows: Coxa Basis Exopod Endopod</p> <p>1 2 3 1 2 3 Leg 1 0-1 0-1 I-1; I-1; II, I, 4 0-3; 1, 2, 3 Leg 2 0-1 0-0 I-1; I-1; III, I, 5 0-3; 2, 2, 4 Leg 3 0-1 0-0 I-1; I-1; III, I, 5 0-3; 2, 2, 4 Leg 4 0-1 0-0 I-1; I-1; III, I, 5 0-1; 0-2; 2, 2, 3 Leg 5 (F) 0-0 0-0 I-0; I-0; II, I, 4 0-1; 0-1; 2, 2, 2 Male (allotype). Body (Fig. 6 A) robust, prosome plump, widest at posterior border of second pediger; prosome about 2.2 times as long as urosome comprising cephalosome and five pedigerous somites; cephalosome distinctly separated from first pediger; fifth pedigerous somite produced into slightly pointed and slightly asymmetrical corners, extending posteriorly slightly further on left side (Fig. 6 A). Rostrum bearing long pair of frontal filaments sinuate at distal part and terminally directed postero-ventrally (Figs 6 B, 7A). Urosome (Fig. 6 C) comprising 4 free somites, symmetrical except for genital somite with single gonopore opening posterolaterally on left side ventral surface; anal somite slightly shorter than 2 preceding free somites. Caudal rami (Fig. 6 C) symmetrical, about 2.3 times longer than wide.</p> <p>Right antennule (Fig. 6 D) 21-segmented, geniculate between segments XX and XXI (18 and 19). Ancestral segments XIX (17) and XX (18) with row of spinules produced from anterior margin respectively; segment XXI (19) with row of relatively longer spinules on proximal 1/3 terminating in long spine along segment margin. Armature as follows: (1) = 2 + ae, (2) = 2+ ae, (3) = 2 + ae, (4) = 2 + ae, (5) = 2 + ae, (6) = 2 + ae, (7) = 2 + ae, (8) = 1 + ae, (9) = 2 + ae, (10) = 2 (1 spiniform) + ae, (11) = 1 + ae, (12) = 2 (1 spiniform) + ae, (13) = 2 + ae, (14) = 2 + ae, (15) = 2 + ae, (16) = 2 + ae, (17) = 1 + ae, XX (18) = 1 + ae, (19) = 1 + process + ae, (20) = 2+ 2, (21) = 6 + ae.</p> <p>Mouthpart appendages, legs 1 to 3 similar to those in female. Leg 4 asymmetrical, basis of right leg with three rounded digitiform processes spreading along lateral surface, proximal and middle ones originated from same base (proximal one smaller) (Figs 6 E–F, 7B); these digitiform processes outlined with papilla-like structures (Fig. 7 B).</p> <p>Leg 5 (Fig. 6 G) strongly asymmetrical; first endopodal segment of both legs produced distolaterally into rounded process. Left leg biramous, with 2-segmented heavily sclerotised exopod and 3-segmented endopod; second exopodal segment nearly 2.3 times as long as first one, hirsute on posteromedial surface, bearing 2 lateral spines, one medial pointed process and bilaterally serrated, long distal spine fused to segment (Fig. 7 C). Right leg (Fig. 6 G) biramous, with broader basis than that of left leg; exopod 3-segmented; first exopodal segment short, with lateral articulated spine and adjacent pointed process distolaterally; second exopodal segment with short spine very near distolateral corner and with strongly-curved inner process originating at nearly 90 degree proximally on to medial margin; third exopodal segment long, curved inward, serrated along outer convex margin (Figs 6 G, 7D), armed with slender seta on proximomedial margin and recurved distally; endopod exceeding second exopodal segment, second endopodal segment with pointed distolateral process. Setal formula of right endopod same as left endopod (0-1; 0-1; 2-2-2); right endopod slightly wider than left one.</p> <p> <b>Molecular diversity.</b> A 544-bp region of the mtCOI was obtained for three individuals of <i>C. mohamedi</i> (GenBank accession Nos. KM288701 - KM288703) collected from the coastal water off Obhur Creek, central Red Sea and four individuals of <i>C. orsinii</i> collected from Obhur Creek (GenBank accession Nos. KM288704 - KM288707). Individuals from the same species have identical mtCOI sequences (0.000), while individuals of different species differed by 20.8 % (Table 1). The mtCOI gene tree also showed that <i>C. mohamedi</i> is clearly an undescribed species separate from <i>C. orsinii</i> (Fig. 8).</p> <p> <b>Etymology.</b> The specific name <i>mohamedi</i> is dedicated to the first author’s son (Mohamed) who passed away on May 2009 at 5 years old.</p>Published as part of <i>El-Sherbiny, Mohsen M. & Al-Aidaroos, Ali M., 2015, A new species of Centropages (Copepoda: Calanoida: Centropagidae) from the central Red Sea based on morphological and molecular evidence, pp. 396-410 in Zootaxa 3911 (3)</i> on pages 397-405, DOI: 10.11646/zootaxa.3911.3.6, <a href="http://zenodo.org/record/233716">http://zenodo.org/record/233716</a&gt

The Red Sea species of Cymo de Haan, 1833 (Decapoda, Brachyura, Xanthidae), associates of scleractinian corals

Brösing, Andreas, Al-Aidaroos, Ali M., Türkay, Michael (2014): The Red Sea species of Cymo de Haan, 1833 (Decapoda, Brachyura, Xanthidae), associates of scleractinian corals. Zootaxa 3779 (2): 195-214, DOI: http://dx.doi.org/10.11646/zootaxa.3779.2.

FIGURE 4 in The Red Sea species of Cymo de Haan, 1833 (Decapoda, Brachyura, Xanthidae), associates of scleractinian corals

FIGURE 4. Cymo andreossyi, gastric teeth (Saudi Gulf, SMF 41726), A, dorso-median view on the right lateral tooth; B, lateral view on the accessory teeth in front of the lateral tooth; C, ventral view on the dorsomedian tooth; D, anterodorsal view on the cardiopyloric valve; acc., accessory teeth; at., anterior; cpv., cardio-pyloric valve; ls., lateral spine; ltc., large teeth cusp; pt., posterior; tl., transverse lamellae; ttc., transverse teeth cusp; uo., urocardiac ossicle; *, mesially directed cusps. Scale bars: A, C, D = 300 µm; B = 100 µm.Published as part of Brösing, Andreas, Al-Aidaroos, Ali M. & Türkay, Michael, 2014, The Red Sea species of Cymo de Haan, 1833 (Decapoda, Brachyura, Xanthidae), associates of scleractinian corals, pp. 195-214 in Zootaxa 3779 (2) on page 201, DOI: 10.11646/zootaxa.3779.2.5, http://zenodo.org/record/25107

Zoeal stages of Hiplyra variegata (Rüppell, 1830) (Crustacea: Brachyura: Leucosiidae) reared in the laboratory and collected from plankton at Al-Kharrar creek, central Red Sea

Al Aidaroos, Ali M., Al Haj, Ahmed E., Türkay, Michael (2015): Zoeal stages of Hiplyra variegata (Rüppell, 1830) (Crustacea: Brachyura: Leucosiidae) reared in the laboratory and collected from plankton at Al-Kharrar creek, central Red Sea. Journal of Natural History 50: 649-660, DOI: 10.1080/00222933.2015.1079656, URL: http://dx.doi.org/10.1080/00222933.2015.107965