
Fig. 1.
Site map of recently discovered Grande Island.
Table 1.
Morphometric measurements of 3rd stage larvae of Anisakis typica collected from the Northern whiting, Sillago sihama in the present study.
| Characters | Measurements (mm) | ||
|---|---|---|---|
| Male | Female | ||
| Body | L: | 3.89–5.366 (4.98±0.28) | 8.49–9.82 (7.57±2.79) |
| Body | W: | 0.036–0.043(0.039±0.01) | 0.18–0.37(0.27±0.009) |
| Buccal tooth | L: | 0.0054–0.0072(0.0063±0.004) | 0.009–0.012(0.010±0.003) |
| Head |
|
|
|
| Buccal cavity | Deep: | 0.016–0.019(0.018±0.002) | 0.018–0.020(0.19±0.004) |
| W: | 0.014–0.018(0.016±0.009) | 0.016–0.019(0.017±0.003) | |
| Oesophagus | i. Anterior | 0.25–0.27(0.26±0.06) | 0.27–0.32(0.29±0.08) |
| 0.036-0.043(0.039±0.002) | 0.041–0.052(0.046±0.02) | ||
| ii.Posterior | 0.18–0.19(0.18±0.007) x 0.054–0.064 (0.059±0.006) | 0.21–0.25(0.23±0.1) x 0.060–0.064 (0.062±0.01) | |
| Intestine | W: | – | 0.28–0.609 (0.57±0.08) x 0.065–0.099 (0.087±0.03) |
| Intestinal caecum |
|
|
|
| Ventriculus |
|
|
|
| Ventricular appendix |
|
|
|
| Distance of anus from tail tip | 0.033-0.039(0.034±0.004) | 0.039–0.041(0.040±0.01) | |
| Mucron |
|
|
|
| Ratio of Caeca : Ventricular Appendix | 1:1.92 | 1:1.84 | |
| Weight/Length ratio of ventriculus | 1:2.2 | 1:2.12 | |
| Length ratio of ventriculus : ceca | 1:0.086 | 1:0.080 | |
Table 2.
Comparative chart of measurements of Anisakis 3rd stage larvae infesting different hosts, inclusive of those given in earlier reports.
| Authors | Anisakis spp. | Host | Body | No. of Examined Hosts | Oesophagus Length | Ventriculus Length | Mucron Length | |
|---|---|---|---|---|---|---|---|---|
| Length | Width | |||||||
| Hurst (1984) | Anisakis simplex 3rd stage larvae | Fish (Thyrsites atun) | 20.26±3.04 | - | - | 1.99±0.21 | 0.69±0.09 | 0.023±0.004 |
| Larizza and Vovlas (1995) | Anisakis simplex | Merluccius merluccius | 21.60±3.47 | 0.41±0.05 | - | 2.65±0.29 | 0.70±0.08 | 0.11±0.01 |
| Quiazon, Yoshinaga, Ogawa, and Yukami (2008) | Anisakis pegreffii | Delphinus delphis | 11.10–26.78 | 0.38–0.60 | - | 1.04–2.11 | 0.50–0.78 | 0.02–0.03 |
| Quiazon, Yoshinaga, Ogawa, and Yukami (2008) | Anisakis simplex | Delphinus delphis | 12.75–29.94 | 0.45–0.75 | - | 1.18–2.58 | 0.90–1.50 | 0.02–0.03 |
| Setyobudi, Jeon, Lee, Seong, and Kim (2011) | Anisakis simplex | Oncorhynchus keta | 23.62±1.87 | 0.56±0.04 | - | 2.06±0.25 | 1.14±0.13 | 0.021±0.004 |
| Pardo-Gandarillas, Lohrmann, Valdivia and Ibáñez (2009) | Anisakis physeteris | Etmopterus spinax | 27–33 | 0.63–0.74 | - | 1.82–2.89 | 0.53–0.65 | 0.17–0.32 |
| Murata, Suzuki, Sadamasu and Kai (2011) | Anisakis paggiae | Beryx splendens | 18.22±2.28 | 0.54±0.07 | - | 1.59±0.19 | - | - |
| Setyobudi, Jeon, Lee, Seong, and Kim (2011) | Anisakis simplex | M. merluccius lessepsianus | 20.4±1.2 | 0.55±0.02 | - | 2.12±0.20 | 0.82±0.1 | 0.025±0.02 |
| Abou-Rahma et al. (2016) | Anisakis simplex | Merluccius merluccius lessepsianus | 14.1–25.6 | 0.48–(20.4±1.2) 0.62 (0.55±0.02 | 60 | 1.18–2.68 (2.12±0.2) | 0.71–0.92 (0.82±0.1) | 0.019–0.032 (0.025 ± 0.02) |
| Roca-Geronesa, Segoviab, Godinez-Gonzaleza, Fisaa and Montoliua (2020) | Anisakis pegreffii | Trachurus trachurus (Horse mackerrel) | 16.9±0.52 | 0.45±0.06 | - | 1.70–1.86 | 0.19–0.31 | 0.05–0.12 |
| Roca-Geronesa, Segoviab, Godinez-Gonzaleza, Fisaa and Montoliua (2020) | Anisakis simplex | Trachurus trachurus (Horse mackerrel) | 17.7±0.21 | 0.45±0.001 | - | 1.39–2.45 | 0.71–1.15 | 0.05–0.13 |
| Hien, HV, Dung, BT, Ngo, HD & Doanh, PN (2021) | Anisakis simplex | Merluccius merluccius | 18.60±1.3 | 0.29±0.00 | - | 18.60+1.1x 0.64±0.04 | 1.54±0.03x 0.64±0.04 | 0.025±0.005 |
| Mostafa (2023) | Anisakis simplex | Delphinus delphis | 18.0±2.1 | 0.45±0.02 | - | 1.35±0.02 | 1.35±0.02 | 0.018±0.002 |
| Author's study (2024) | Anisakis typica 3rd stage Larvae | Sillago sihama | 7.57±1.79 | 0.25±0.06 | 49 | 0.44±0.05 | 0.018–0.023 (0.023±0.007) | 0.033–0.041 (0.040±0.01) |
Table 3.
Frequency of consumption of various non-vegetarian food items reported by households in Kerala.
| Attributes | Percentage | Fresh Prawn | Dried Fish | Dried prawn |
|---|---|---|---|---|
| Never | 100% | - | ||
| Others | 90–100% | 62 | 182 | 196 |
| On special occasions | 30–80% | 209 | 104 | 77 |
| More than once a week | 10–30% | 91 | 121 | 141 |
| Almost Everyday | 0–10% | 49 | - | - |
Table 4.
Per capita monthly consumption of fish v/s other meat in Malappuram, Kerala.
| S. No. | Items consumed | Per capita consumption (kg/month) |
|---|---|---|
| 1. | Fish | 2.6 |
| 2. | Chicken | 0.8 |
| 3. | Beef | 0.6 |
| 4. | Mutton | 0.4 |
| 5. | Pork | 0.0 |
Table 5.
Most purchased fish species in Malappuram, Kerala.
| S. No. | Fish Species | Purchased by (%) |
|---|---|---|
| 1. | Sardine | 91 |
| 2. | Mackerel | 60 |
| 3. | Sole fish | 20 |
| 4. | Cod fish | 14 |
| 5. | Squid | 8.5 |
| 6. | Prawns | 8 |
| 7. | Tuna | 6.5 |
| 8. | Pomfret | 5.5 |
| 9. | Tilapia | 4.5 |
| 10. | Seer fish | 4 |
| 11. | Shark | 3.5 |
| 12. | Malabar trevally | 3 |
| 13. | Threadfin bream | 2.5 |
| 14. | Clams | 1.5 |
| 15. | Pearl spot | 1 |
| 16. | Ribbon fish | 1 |
Table 6.
Representative groups of ITS2 gene sequences selected for the study.
| GenBank Accession No. | Gene | Taxon | Reference |
|---|---|---|---|
| JQ798962 | ITS2 | Anisakis typica | Borges et al. (2012) |
| MT635343 | ITS2 | Anisakis typica | Borges et al. (2021) |
| ON065560 | ITS2 | Anisakis typica | Bao et al. (2022) |
| LN651099 | ITS2 | Anisakis typica | Shamsi et al. (2015) |
| KF633462* | ITS2 | Anisakis typica | Present study |
| KY524217 | ITS2 | Anisakis typica | Palm et al. (2017) |
| JQ912692 | ITS2 | Anisakis nascettii | Mattiucci et al. (2014) |
| FN556997 | ITS2 | Anisakis sp. | Shamsi et al. (2012) |
| FR716448 | ITS2 | Anisakis pegreffii | Shamsi (Unpublished) |
| LC745135 | ITS2 | Anisakis simplex | Ikebuchi (Unpublished) |
| LC666445 | ITS2 | Anisakis sp. | Hirata et al. (Unpublished) |
| MK325217 | ITS2 | Anisakis sp. | Shamsi et al. (2019) |
| MF768443 | ITS2 | Anisakis sp. | Quiazon et al. (Unpublished) |
| MF358544 | ITS2 | Anisakis simplex | Cipriani et al. (2017) |
| HQ616674 | ITS2 | Anisakis simplex | Meloni et al. (2011) |
| JF424598 | ITS2 | Contracaecum bioccai | D'Amelio et al. (Unpublished) |
| KY018601 | ITS2 | Hysterothylacium aduncum | Pawlak et al. (2018) |
| KY524217 | ITS2 | Anisakis typica | Palm et al. (2017) |

Fig. 2.
Neighbour-joining tree based on nucleotide ITS2 sequences and reference species. Nucleotide ITS2 sequence data are as described in the text with GenBank accession numbers. Bootstrap values based on 1000 replicates were used. Scale bar represents an interval of the Kimura two-parameter (K2P) model.
*Current investigation

Fig. 3.
Neighbour-joining tree based on nucleotide ITS1 sequences and reference species. Nucleotide ITS1 sequence data are as described in the text with GenBank accession numbers. Bootstrap values based on 1000 replicates were used. Scale bar represents an interval of the Kimura two-parameter (K2P) model.
*Current investigation
Table 7.
Representative groups of ITS1 gene sequences selected for the study.
| GenBank Accession No. | Gene | Taxon | Reference |
|---|---|---|---|
| KX098561 | ITS1 | Anisakis typica | Andres et al. (2016) |
| JX848665 | ITS1 | Anisakis typica | Jabbar et al. (2017) |
| MF642336 | ITS1 | Anisakis typica | Shamsi et al. (2017) |
| AB479120 | ITS1 | Anisakis typica | Umehara et al. (Unpublished) |
| AB432909 | ITS1 | Anisakis typica | Umehara et al. (Unpublished ) |
| MW315550 | ITS1 | Anisakis typica | Suthar and Shamsi (2021) |
| KF633459 | ITS1 | Anisakis typica | Present study* |
| JQ912692 | ITS1 | Anisakis nascettii | Mattiucci et al. (2014) |
| LC621351 | ITS1 | Anisakis simplex | Sato et al. (Unpublished) |
| FN557239 | ITS1 | Anisakis sp. | Shamsi (Unpublished) |
| FN557233 | ITS1 | Anisakis sp. | Shamsi (Unpublished) |
| FN391859 | ITS1 | Anisakis pegreffii | Shamsi et al., (2012) |
| MF358544 | ITS1 | Anisakis simplex | Cipriani et al., (2017) |
| JF424598 | ITS1 | Contracaecum bioccai | D'Amelio et al., (Unpublished) |
| HQ616674 | ITS1 | Anisakis simplex | Meloni et al.,(2011) |
| HQ616675 | ITS1 | Anisakis simplex | Meloni et al.,(2011) |
| KY018601 | ITS1 | Hysterothylacium aduncum | Pawlak et al.(2018) |
| KY524217 | ITS1 | Anisakis typica | Palm et al.(2017) |
| KY524213 | ITS 1 | Anisakis typica | Palm et al. (2017) |

Fig. 4.
Neighbour-joining tree based on nucleotide 18S rDNA sequences and reference species. Nucleotide 18S rDNA sequence data are as described in the text with GenBank accession numbers. Bootstrap values based on 1000 replicates were used. Scale two-parameter (K2P) model.
*Current investigation
Table 8.
Representative groups of 18S rDNA gene sequences selected for the study.
| GenBank Accession No. | Gene | Taxon | Reference |
|---|---|---|---|
| JF412028 | 18S rDNA | Anisakis simplex | Lalle et al.(Unpublished) |
| AY821739 | 18S rDNA | Anisakis simplex | Nadler et al., (2004) |
| AB277821 | 18S rDNA | Anisakis physeteris | Umehara et al.,(2008) |
| EU624343 | 18S rDNA | Anisakis pegreffii | Quiazon et al.,(2008) |
| EU624342 | 18S rDNA | Anisakis simplex | Quiazon et al., (2008) |
| AY826724 | 18S rDNA | Anisakis typica | D'Amelio et al.,(Unpublished) |
| AB432908 | 18S rDNA | Anisakis typica | Umehara et al., (2008) |
| AB479120 | 18S rDNA | Anisakis typica | Umehara et al., (2010) |
| JX523715 | 18S rDNA | Anisakis typica | Zhang et al.,(2013) |
| KC928262 | 18S rDNA | Anisakis typica | Anshary et al., (2014) |
| KF636791* | 18S rDNA | Anisakis typica | Jaiswal et al., (2013) |
| EF180082 | 18S rDNA | Anisakis pegreffii | Nadler et al., (2007) |
| JQ798962 | 18S rDNA | Anisakis typica | Borges et al., (2012) |
| HE997162 | 18S rDNA | Anisakis pegreffii | De Luca et al., (Unpublished) |