Digenetic trematodes of marine fishes from the Kuwaiti coast of the Arabian Gulf

D~ring July and August 1978, 165 fishes belonging to 35 species in 19 families were collected from the Kuwaiti coast of the Arabian Gulf and examined for parasites. Nine digenetic trematodes including three new species and two new genera are described: (Hemiuridae) Opisthadena kuwaiti, n.sp. from Valamugil seheli, Lecithocladium bulbolabrum Reid, Coil and Kuntz, 1966 from Johnius aneus (new host record), 1· unibulbolabrum Fischthal and Thomas, 1971 from Rastralliger kanagurta (new host record), Clupenuroides sheemi n.g., n.sp, from Eleutheronema tetradactylum; (Angiodactylidae) Hexangium sigani Goto and Ozaki, 1929 from Sigartus oramin; (Pleorchiidae) Pleorchis arabicus n.sp. from Otolithes argenteus; (Opecoelidae) Helicometrina nimia Linton, 1910, from Nemipterus tolu (new host record) and Plagioporus sp. from Nemipterus tolu; (Acanthocolpidae) Stephanostomum sp. from Lutjanus coccineus. Keys to the species of Opisthadena and Pleorchis, and to certain closely related dinurid genera are given. E_. puriensis Gupta and Ahmad, 1976 is transferred to the new genus Parapleorchis

Digenetic trematodes of marine fishes from the Kuwaiti coast of the Arabian Gulf

D~ring July and August 1978, 165 fishes belonging to 35 species in 19 families were collected from the Kuwaiti coast of the Arabian Gulf and examined for parasites. Nine digenetic trematodes including three new species and two new genera are described: (Hemiuridae) Opisthadena kuwaiti, n.sp. from Valamugil seheli, Lecithocladium bulbolabrum Reid, Coil and Kuntz, 1966 from Johnius aneus (new host record), 1· unibulbolabrum Fischthal and Thomas, 1971 from Rastralliger kanagurta (new host record), Clupenuroides sheemi n.g., n.sp, from Eleutheronema tetradactylum; (Angiodactylidae) Hexangium sigani Goto and Ozaki, 1929 from Sigartus oramin; (Pleorchiidae) Pleorchis arabicus n.sp. from Otolithes argenteus; (Opecoelidae) Helicometrina nimia Linton, 1910, from Nemipterus tolu (new host record) and Plagioporus sp. from Nemipterus tolu; (Acanthocolpidae) Stephanostomum sp. from Lutjanus coccineus. Keys to the species of Opisthadena and Pleorchis, and to certain closely related dinurid genera are given. E_. puriensis Gupta and Ahmad, 1976 is transferred to the new genus Parapleorchis

Distributional ecology of zooplankton and fish larvae (spot, croaker, menhaden) in the northern Gulf of Mexico

Ichthyoplankton and zooplankton samples were collected during February of three years, 1980, 1981 and 1982, in the northern Gulf of Mexico. The objectives were to describe density distributional patterns of fish larvae and the zooplankton organisms which serve as prey for the larvae. Emphasis was placed on the larvae: spot (Leiostomus xanthurus), Atlantic croaker (Micropogonias undulatus) and Gulf menhaden (Brevoortia patronus). Three transect lines were sampled: offshore from the Mississippi River delta, offshore from Cape San Blas, Florida and offshore from Galveston, Texas. Stations at 10F, 50F and 100F isobaths were sampled along each transect and samples were obtained at 0600, 1200, 1800 and 2400 hours. Three discrete depths were sampled at each station.The three target species and their zooplankton prey displayed signficant inter-annual variations, inshore-offshore gradients, and different vertical depth distributions. Menhaden larvae were more abundant than spot and croaker larvae at 5 out of 9 stations sampled. At the remaining 4 stations, the three target species displayed comparable densities. Menhaden larvae constituted 64% of total larvae at the Mississippi-10F station, 39.6% at the Mississippi-50F and 30.7% at the Mississippi-100F station. Highest densities of spot (12.5/1000 m3), croaker (9.0/1000 m3), and menhaden larvae (916.8/1000 m3) were found at the Mississippi-10F station, in the vicinity of the Mississippi River delta. Average densities of the three most abundant zooplankters: copepod nauplii (8284/m3), small copepods (8558/m3) and pelecypod larvae (1554/m3) were not distinctly high when compared with the Cape San Blas-10F inshore station. However, maximum densities of nauplii, pelecypod larvae and ciliates were encountered at the Mississippi-10F station, indicating that subregions within the Mississippi River delta with good larval feeding conditions exist. Also, the Mississippi inshore station is distinguished from the other inshore stations, by the stratified nature of its water column.Spot, croaker and menhaden larvae displayed different vertical distributions. Croaker larvae were uniformly distributed, spot larvae were more numerous at the surface during midnight, only at the Mississippi-10F station, and menhaden larvae were discernibly more numerous at the surface at noon at all the three inshore stations and at the Mississippi-50F station, where larvae occurred also at the surface during midnight. (Abstract shortened with permission of author.

Analysis of the relationship between phytoplankton biomass and the euphotic layer off Kuwait, Arabian Gulf

416-423The Kuwait Bay is a shallow tidally well-mixed sub-tropical environment in the Arabian Gulf, and is characterized by excessive evaporation, little freshwater input, and several anthropogenic disturbances attendant with oil explorations. From the Gulf we examined 219 Secchi disc readings and profiles of temperature, salinity, chlorophyll a, and nutrients. Features of interest are: a) existence of marked differences in the magnitude of phytoplankton biomass between the nearshore (3.8 -113.4 mg chi a m-2) and offshore stations (4.5 - 57.9 mg chi a m-2), b) lower algal biomass (18 .5 to 27.3 mg chi a m-2) at 3 inshore stations located off an industrial belt compared to offshore waters (&gt;42 mg chi a m-2), c) absence of pronounced seasonal phytoplankton growth and d) small increases in biomass sometime during March - May, August and October - December. An analysis of the relationship between scaled critical depth, integrated chlorophyll a and nutrients support the hypothesis that phytoplankton biomass in Kuwait waters, in general, was not restrained by physical environment. The correlation coefficient (Spearman Rank) for the sign trend test between scaled critical depth (Z'cr) and integrated chlorophyll a was not significant at 10 stations suggesting dependence of phytoplankton abundance on factor(s) other than light. Only at an offshore station (#18) this correlation was negative and significant. Light profiles yielded 83-275 W m-2 near the bottom suggesting availability of sufficient light for algal growth in these well-mixed sub-tropical shallow waters.</span

Bestiolina arabica sp. nov. (Copepoda, Calanoida, Paracalanidae), a new species from the northwestern Arabian Gulf

A new species, Bestiolina arabica sp. nov. is described from the northwestern Arabian Gulf. The species can be distinguished from its congeners by the lack of large spinules on the anterior face of the exopods of swimming legs 2-4 in both sexes, and the lack of marginal spinules on the endopods of those same legs. © 2007 Brill Academic Publishers

The effect of tidal cycles on the community structure of plankton (with emphasis on copepods) at AFMED Marina in winter (a preliminary study)

Tidal cycles had no significant effect on the abundance or community structure of plankton at AFMED (Aquaculture, Fisheries and Marine Environment Department) Marina, nor had any physicochemical factor, except salinity, on the density of copepods (p \u3c 0.05), although variation in the physichochemical data measured was small. The major components of the plankton community throughout the study were copepods, Noctiluca spp. (mostly N. scintillans (Macartney) Kofoid & Swezy), and cirripede nauplii. Their abundance differed between high and low tides throughout the study. Variation between high and low tides was also observed among the various groups and species of copepods. MDPs (Mean Density Percentages) of calanoids, copepod nauplii, and poecilostomatoids were higher at high tide (45%, 20.09%, and 2.81%, respectively), while cyclopoid and harpacticoid MDPs were higher at low tide (30.63% and 9.95%, respectively). The most dominant copepods were Parvocalanus crassirostris (F. Dahl, 1894), Paracalanus spp., Oithona simplex Farran, 1913, Euterpina acutifrons (Dana, 1847), Oncaea spp., and Corycaeus spp. The copepods with the highest MDPs at high tide were Parvocalanus crassirostris (14.19%), Paracalanus spp. (10.79%), Oncaea spp. (1.75%) and Corycaeus spp. (1.06%), respectively, while Oithona simplex and Euterpina acutifrons had a higher MDP at low tide (14.97% and 9.12%, respectively). The highest MDP at low tide was that of Oithona simplex. Neither tide nor any other factor measured had a significant effect on any of the copepods. Other, related factors (mainly biological and anthropogenic) may thus have accounted for the differences in abundance and biodiversity observed. © 2011 Koninklijke Brill NV, Leiden

Space-time variability of phytoplankton structure and diversity in the north-western part of the Arabian Gulf (Kuwait)

Studies of the phytoplankton community were conducted in the north-western Arabian Gulf in 2005 and 2006. Seven stations throughout Kuwait’s waters were sampled. The influence of nutrient-rich freshwaters from the Shatt al-Arab resulted in high phytoplankton productivity characterized by high species diversity with a strong dominance of diatoms, especially in northern Kuwait. Phytoplankton species richness gradually increased from north to south. Spatial distribution of both total abundance and biomass of phytoplankton indicated significant differences in species structure and size spectrum of the microalgae. The analysis of the temporal and spatial phytoplankton variability (distribution of total abundance and biomass, similarity of species compositions and local community structure) indicated that Kuwait’s northern waters differed from areas further south in terms of phytoplankton structure and temporal and spatial variability. Environmental heterogeneity is mainly attributed to the influence of the Shatt al-Arab system, which affects the temporal and spatial variability of the phytoplankton community

Biodiversity of free-living flagellates in Kuwait’s intertidal sediments

Taxonomic data of free-living benthic flagellates in Kuwait’s intertidal sediments are summarized. A full list of the species composition is presented, including distribution on different sediment types, species occurrence and light micrographs for each taxon identified. A total of 67 flagellate species were identified, representing six classes. Most of them are reported from Kuwait for the first time. The most abundant and diverse species were sand-dwelling dinoflagellates (43 taxa)

Growth and photosynthetic rates of Chlamydomonas plethora and Nitzschia frustula cultures isolated from Kuwait Bay, Arabian Gulf, and their potential as live algal food for tropical mariculture

With a view to utilize local algae as food organisms in mariculture, the green alga Chlamydomonas plethora and the diatom Nitzschia frustula were isolated and studied from the unique coastal waters arid zone off Kuwait. Batch cultures of C. plethora and N. frustula had maximum division rates (lmax) of 2.5 and 3.4 day)1, respectively. Cultures grown for 36 h yielded comparable growth rates. Photosynthesis-irradiance relationships in cultures harvested at various phases of growth showed that cultures attained log phase after 1-day growth and yielded the highest assimilation numbers (PB m: lg C [lg Chl a])1 h)1): 22.8 for C. plethora and 18.1 for N. frustula. Their initial slopes (aB: ng C [lg Chl a])1 h)1 [lmol m)2 s)1])1 were also the highest observed so far: 79.5 for C. plethora and 39.6 for N. frustula. Photoinhibition was low. Compared with these, assimilation numbers in senescent cultures of 20-day growth were <8% of the maximum for both species, and the initial slope decreased to 17 and 13% in C. plethora and N. frustula, respectively. Two polyunsaturated fatty acids (20:5n-3 eicosapentaenoic acid and 22:6n-3 docosahexaenoic acid) that are essential in many marine animal diets constituted up to 24% and 1.9% of the total fatty acids, respectively. Of the two algae, N. frustula contained higher levels of 16:1n-7, 20:5n-3 and comparatively low levels of 22:6n-3 fatty acids. Due to its rapid growth, high photosynthetic rate and presence of the amino acids leucine, lysine, glutamic acid and arginine N. frustula has good potential as a feed organism in mariculture applications. The capacity of these algae to produce a wide range of size groups (nano and net plankton) is an additional bonus for mariculture operations.Peer reviewed: YesNRC publication: Ye