sheikheldin M O H A M E D Elamin

Some biochemical studies (protein, fat, moisture and ash) were done on three species of holothurians namely Holothuria scabra, Actinopyga echinites and Holothuria atra, which were collected from Abu Hashish and Kilo Tammania areas in Sudanese Red Sea. Statistical analysis showed that there was a significant difference (P<0.05) in moisture, ash and protein content of the air-dried and processed animals. However, a non-significant difference (p>0.05) in fat content is encountered. Differences in moisture and fat content of H. atra collected from the two sites are insignificant while the difference in protein and ash contents are significant. All the measured contents in A. echinites are assumed not to differ significantly between the two areas except in their fat content.

The paper focused on the morphometric data of Siganus rivulatus and Siganus stellatus which determine the relationship between body measurements and total length and to show correlation and significant differences between males and females for these species which inhabit around Abu Hashish area in Sudanese Red Sea. A total of 411 specimens of Siganus rivulatus and 39 of S. stellatus were collected during the period from February 2005 to January 2006. There was a significant difference (p<0.05) in the morphometric measurements between both sexes of S. rivulatus except for eye diameter which was insignificant (p>0.05), while for S. stellatus there is significant difference between both sexes in total length, head length. In both females and males the correlation between total length and standard length and head length and standard length of S. rivulatus were very highly significant (p<0.000), while for females and males of S. stellatus it was very highly significant (p<0.000) between total length and standard length, head length and standard length and body depth and standard length.

Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh Triaenodon obesus and Hipposcarus harid fish were purchased from Port Sudan fish central market during December 2014. The fatty acid profiles of the livers of these commercially important fish were determined. The polyunsaturated and saturated fatty acids ratio in the livers oil of T. obesus and H. harid was 1:2.2 and 1:1.38, respectively. The Palmatic (16:0), Pentadecenoic (12:0) and Arachidic acids were the highest in both species. The poly chain unsaturated fatty acids Linolenic (18:3n − 3), Eicosapentaenoic (20:5n − 3) and Docosahexaenoic (22:6n − 3) were detected in the liver of both species. The highest values of above poly chain unsatu-rated fatty acids were detected in T. obesus.

The present study was conducted at six stations around Port Sudan Harbour to correlate total macro zooplankton with the physical and chemical parameters in samples from the Sudanese Red Sea. Oxygen, transparency and NO3 showed positive correlation with total numbers of zooplankton. The impact of other parameters varies from one station to the other with highest frequency for oxygen followed by NO3 and pH. Calanoida Copepods and Cyclopoida Copepods were the dominant groups and Cladocerans were the least recorded from 15 identified group of zooplankton.

Lethrinus harak (Forsskal 1775) are very common species of the family Lethrinidae in Sudanese Red Sea Coast. Some aspects of the reproductive biology and histology of the gonads of Lehtrinus harak were studied between 2008 and 2009. The present study described six maturity stages for gonad development based on external features and histological study of males/females. Males of Lethrinus harak attain maturity stages at a relatively bigger size than females (at 22.5 cm for males and 21.7 cm for females). Lethrinus harak has a prolonged spawning season extending from October to April with peaks in April.

Pinctada margaritifera is naturally occurring in Dungonab Bay and its adjacent areas. Its growth was studied for an annual cycle, from January to December 2010 in hanging, bottom and ground culturing systems as well as from the wild oysters. The asymptotic shell highest (H∞) was 27.59, 9.55 and 7.77 cm in the hanging, bottom and ground system, respectively. In the wild it was 27.59 cm. The growth Index Ф was 4.39, 3.97 and 3.94 in the hanging, bottom and ground system, respectively. In the wild it was 3.66. The average heights shell increment was 0.80, 0.62 in April and 0.48 cm in March in the hanging, bottom and ground system, respectively. The lowest shell increment was 0.00, 0.09 in August and 0.21cm in the ground, bottom and the hanging system, respectively. The linear plot of H (t +∆t) against Ht, for hanging, bottom, and ground culture system as well as and wild oysters yielded very highly significant correlation (p<0.001; r = 0.969-0.997). The linear plot of the relationship between t and-ln (1-Ht /H∞) in all system yielded very highly significant correlation (p<0.001; r = 0.990-0.998). In all groups, the increase in shell length with time is slow and variable.

Size-free meristics and morphometric characters are valid tools to identify species, genera and fish stock units. Morphometric characters are not sensitive to short-term, local fluctuations, and reflect average differences over long periods between environmental factors in different areas. The present work is aims to study some morphometric measurements and the relationship and the ratios propositional measurements for E. chlorostigma, which locally known as "Shoni". A total of 269 specimens with total length ranged from 17 cm to 62.9 cm were collected randomly from Port Sudan central fish market from landed fish caught by the artisanal fishermen around Dongonab Bay and Mukkawar Island Marine National Park (DBNP). Monthly samples were taken from January 2014 to April 2015. Twelve body measurements were taken such as; (TL), standard length (SL), depth (D), and girth (G). Comparison of descriptive statistics of five body measurements; (SL.:D, SL. : HL, HL.: PFL, HL.:PVFL and HL.:CPD) showed that the mean ratios of measurements were in the ranged values. Most relationships of morphogenetic measurements against the total length appeared that there is a strong correlation; their R2 values ranged from 0.860 for TL Vs CPD to 0.992 TL Vs SL respectively while the rest were ranged from 0.311 for TL Vs OMW to 0.471 for TL Vs ED. All morphometric measurements were strongly correlated with total length. The mean values of all proportions were in the ranges of the identification record of these species.

Some biochemical studies (protein, fat, moisture and ash) were done on three species of holothurians namely Holothuria scabra, Actinopyga echinites and Holothuria atra, which were collected from Abu Hashish and Kilo Tammania areas in Sudanese Red Sea. Statistical analysis showed that there was a significant difference (P<0.05) in moisture, ash and protein content of the air-dried and processed animals. However, a non-significant difference (p>0.05) in fat content is encountered. Differences in moisture and fat content of H. atra collected from the two sites are insignificant while the difference in protein and ash contents are significant. All the measured contents in A. echinites are assumed not to differ significantly between the two areas except in their fat content.

The present study was conducted at six stations around Port Sudan
Harbour to correlate total macro zooplankton with the physical and
chemical parameters in samples from the Sudanese Red Sea.
Oxygen, transparency and NO3 showed positive correlation with
total numbers of zooplankton. The impact of other parameters varies
from one station to the other with highest frequency for oxygen
followed by NO3 and pH. Calanoida Copepods and Cyclopoida
Copepods were the dominant groups and Cladocerans were the
least recorded from 15 identified group of zooplankton.