CHAPTER - IV (Contd.)

TABLE 56: SHOWING MONTHLY PERCENTAGE COMPOSITION OF THE MALES AND FEMALES (SEX-RATIO) OF PENAEID SHRIMPS IN BEHUNDI CATCH (PER KG) AT CHAKARIA.

The figures in the nominator indicate percentage of males and the figures in the denominator indicate percentage of females.

TABLE 57: SHOWING MONTHLY PERCENTAGE COMPOSITION OF THE MALES AND FEMALES (SEX-RATIO) OF PENAEID SHRIMPS IN BEHUNDI CATCH (PER KG) AT KHEPUPARA.

The figures in the nominator indicate percentage of males and the figures in the denominator indicate percentage of females.

TABLE 58: SHOWING MONTHLY PERCENTAGE COMPOSITION OF THE MALES AND FEMALES (SEX-RATIO) OF PENAEID SHRIMPS IN BEHUNDI CATCH (PER KG) AT SATKHIRA.

The figures in the nominator indicate percentage of males and the figures in the denominator indicate percentage of females.

TABLE 59: SHOWING OCCURRENCE OF DIFFERENT SPECIES OF SHRIMPS IN BEHUNDI CATCHES AT CHAKARIA, KHEPUPARA AND SATKHIRA.

+ Rarely present (less than one indiv.)
++ Present (1–5 indivs)
+++ Dominant (5–10 indivs.)
++++ Most dominant (More than 10 indivs.)
- Absent

TABLE 60: SHOWING OCCURRENCE OF DIFFERENT SPECIES OF FISHES AND OTHER ORGANISMS (OTHER THAN SHRIMPS) IN BEHUNDI CATCHES AT CHAKARIA, KHEPUPARA AND SATKHIRA.

+ Rarely present (less than one indiv)
++ Present (1–5 indivs)
+++ Dominant (5–10 indivs)
++++ Most dominant (More than 10 indivs.)
- Absent

7.0 POND HARVEST FISHERY OF THE TWO STUDY AREAS

In the present observation, the seasonal occurrence, abundance and percentage composition of shrimps, finfishes of pond harvest of the two areas were studied and these are shown in Tables 61 – 74. The studies on sex-ration of penaeid shrimps was also noted and is shown in Tables 71 & 72.

In all 10 species of shrimps (belonging to three families) 22 species of fishes (belonging to 17 families) and two species of other organisms were encountered.

SHRIMPS

7.1 Seasonal Occurrence and Distribution of Shrimps in Pond Harvest.

In the present investigation, the higher density of shrimps was found in pondharvest at Satkhira (with a monthly average of 201.82 indv/kg) and it formed 96.56% of total catch. However, in ponds at Chakaria shrimps were less abundant (monthly average of 168.88 indv/kg and 91.16% of total catch (Tables 61 & 62).

At Chakaria, the highest density of shrimps was found in October, 1982 (551 indv/kg) and the lowest in December, 1982 (7 indv/kg), whereas at Satkhira the maximum number of shrimps was found in November, 1982 (596 indv/kg) and the minimum in August, 1983 (61 indvs/kg).

In this study, five species (belong to two genera) of penaeids and four species (belonging to two genera) of carideans were identified in the pondharvest. Penaeus monodon, Metapenaeus monoceros and M. brevicornis were the most abundant species throughout the period in all the study areas. Penaeus indicus was present in both the areas. Among the carideans only Palaemon (E) styliferus was the most abundant species at Satkhira. Macrobrachium rosenbergii was only reported from Satkhira (Table - 73).

The occurrence and distribution of major penaeid shrimps are described in the following lines.

Penaeus monodon: The higher occurrence of this species was obderved at Satkhira (monthly average 12.64 indvs/kg) than Chakaria (monthly average 9.5 indvs/kg). At Chakaria the maximum number was found in June, 1982 (25 indvs/kg) and minimum in January, 1983 (1. indv/kg). However, at Satkhira the highest number was found in July, 1982 (26 indvs/kg) and the lowest in April, 1983 (7 indvs/kg).

Metapenaeus monoceros: This species was found to be dominant throughout the year with a peak in November, 1982 (399 indv/kg) at Satkhira and thelowest was recorded as 9 indv/kg in July, 1983. Whereas at Chakaria, the highest number was found in October, 1982 (428 indv/kg) and the lowest in March, 1983 (10 indv/kg). The maximum yeild was observed at Chakaria (monthly average 130 indv/kg) than Satkhira (88.54 indv/kg).

M. brevicornis: M. brevicornis was also found in a large number in both the areas with the higher population recorded at Satkhira (monthly average 70.64 indv/kg). At Chakaria, the peak abundance was observed in October, 1982 (82 indvs/kg). On the otherhand, the maximum number was found in June, 1983 (159 indvs/kg) and the minimum was in April, 1983 (1 indv/kg).

7.2 Distribution of the Males and Females (Sex-Ratio) of Penaeid Shrimps in Pond Harvest.

The distributions of males and females (Sex Ratio) of different penaeid shrimps in the pond harvest were studied and these are shown in Tables 71 & 72.

It was observed that the males of Penaeus monodon were dominant in August & September, 1982 and January, April and June, 1983 at Chakaria. However, at Satkhira these (males) were dominant in June to September, 1982 and July, 1983.

It was revealed from the present observation that the males of Metapenaeus monoceros were more abundant than the females in May, 1982 and January, June and August, 1983 at Chakaria. At Satkhira females were more dominant in overall distribution. Males were more abundant only in September, 1982 and April, June and August, 1983.

At Chakaria, females of Metapenaeus brevicornis were found to be dominant thoughout the period except in October, 1982 and January 1983. Similar observation was also found at Satkhira where the males were dominant in June, September, 1982 and April 1983.

7.3 Seasonal Occurrence and Distribution of Fishes of Pond Harvest.

In the present study, in total 22 species (belonging to 17 families) of fishes were identified of which only Mugil spp., Glossogobius sp. and Mystus spp. were common in both the areas (Table - 74). The seasonal abundance, distribution and percentage composition of different fishes are given in Tables 64, 66, 68 & 69.

Between the two stations higher density of fishes was obtained at Chakaria with a monthly average of 13.25 indvs/kg. At Satkhira the monthly average distribution of fishes was 4.82 indvs/kg. At Chakaria fishes were noted to be maximum in November, 1982 (37 indvs/kg) and minimum in June and August, 1983 (1 indv/kg) and fish was totally absent in July, 1983.

At Satkhira, highest number of fishes was found in August, 1982 (13 indvs/kg) and a single individual of fish was found in April and July, 1983.

The occurrence and distribution of some important species of fishes obtained in pond harvest are described in the following lines.

Hilsa ilisha and Hilsa Kanagurta: These species were only reported from Chakaria with a rare occurrence. Only a single species of Hilsa ilisha and Hilsa Kanagurta was found in September, 1982 and February, 1983 respectively.

Mugils: Lira tade was recorded only at Chakaria in January and March, 1982 (12 & 1 indvs/kg) respectively) whereas Mugil spp. were scatteredly distributed throughout the year with peak abundances in November, 1982 in both the study areas.

Lates calcarifer: Lates calcarifer was found at Chakaria only. It was first reported in the catches in June, 1982 and was found in December, 1982, March, May, June and August, 1983. The highest number recorded in the areas was 4 indv/kg. in June, 1982.

7.4 Occurrence of Organisms Other Than Shrimps and Fishes of Pondharvest.

Other than shrimps and fishes only two texa, squilla sp. and crab were reported from both the sutdy areas of which squilla sp. was found relatively dominant at Chakaria and crab at Satkhira (Tables 64, 66 & 74).

7.4 Comments:

In the present investigation the higher density of shrimps in pondharvest was recorded at Satkhira (with a monthly average of 201.82 indvs/kg) than that of Chakaria (168.88 indv/kg). Penaeus monldon, Metapenaeus monoceros and M. brevicornis were the dominant species in both the study areas. Penaeus indicus was also present and comparatively more abundant at Chakaria than Satkhira Palaemon (E) styliferus and Macrobrachium rosenbergil were only reported from Satkhira whereas Acetes sp. was totally absent there.

The fishes in pondharvest was found to be more dominant at Chakaria (monthly average 13.25 indvs/kg) than Satkhira (monthly average 4.82 indvs/kg).

Amont the commercial species Hilsa ilisha, Hilsa kanagurta, Liza tade, Lates calcarifer and Cynoglossus sp. were only reported from Chakaria and were less in number. Some species of the genera Mugil and Mystus were also present in both the areas.

It was observed that Lates calcarifer was appeared in June, 1982 and sparsely distributed in December, 1982 and March, May, June and August, 1983 at Chakaria.

TABLE 61 : SHOWING SEASONAL ABUNDANCE OF SHRIMPS FISHES AND OTHER ORGANISMS PER KG OF POND-HARVEST AND THEIR PERCENTAGE COMPOSITION AT CHAKARIA.

TABLE - 62 : SHOWING SEASONAL ABUNDANCE OF SHRIMPS FISHES AND OTHER ORGANISMS PER KG. OF PONDHARVEST AND THEIR PERCENTAGE COMPOSITION AT SATKHIRA.

TABLE 63 : SHOWING MONTHLY OCCURRENCE AND ABUNDANCE OF SHRIMPS PER KG OF POND-HARVEST AT CHAKARIA.

TABLE 64 : SHOWING MONTHLY OCCURRENCE AND ABUNDANCE OF FISHES AND OTHER ORGANISMS (OTHER THAN SHRIMPS) OF PONDHARVEST AT CHAKARIA.

TABLE - 65 : SHOWING MONTHLY OCCURRENCE AND ABUNDANCE OF SHRIMPS PER KG. OF PONDHARVEST AT SATKHIRA

TABLE - 66 : SHOWING MONTHLY OCCURRENCE AND ABUNDANCE OF FISHES AND OTHER ORGANISMS (OTHER THAN SHRIMPS) OF PONDHARVEST AT SATKHIRA.