Fishmeal Replacement with Animal Protein Source (Crocodylus niloticus Meat Meal) in Diets of Mozambique Tilapia (Oreochromis mossambicus) of Different Size Groups
Round 1
Reviewer 1 Report
In the study of Rendani Luthada-Raswiswi and co-workers, the authors evaluated the potential of Crocodylus niloticus meat meal as an animal protein source replacing fishmeal in Oreochromis mossambicus diets. Authors concluded that it was profitable to use Crocodylus niloticus meat meal to replace fishmeal in diets of O. mossambicus of all size groups. This is very meaningful for Mozambique tilapia fry, fingerlings and adult fish farming process to reduce costs of ingredients. However, in my opinion, this work presents several major concerns needed to be revised. After thoroughly modification, this work could be considered for publication in Applied Sciences.
Major concerns
1. The survival rate of experimental fish, especially adult fish, is low. Besides, it is noted that the survival rate (Mean ± SD) in the table even exceeds 100%. What is the reason for such survival rate? Although the author had said in the discussion that the fish jumped out, but the survival rate is low in the feeding trial, the credibility of the experiment and the final sample number will be affected. How to explain?
2. The study focused on the potential of crocodile meal as a substitute for fishmeal, but one limitation mentioned was that the study used commercial diets as control diets. For fishmeal replacement, the group without the control of feed formulation variable was insufficient to serve as a control group. Therefore, it is suggested to explain the role of D1 group and commercial diets group in the methods section of the paper.
3. The time interval between the two feeding times is relatively short, which means that the fish has not been fed for a long time (about 19 hours), will this cause hunger or not? Will this hunger stress the fish? Does it conform to the ethical code?
Minor concerns
1. Line 28: The costs of ingredients mentioned in the abstract may be described more objectively by summarized data.
2. Line 74: The citation format of references should be uniform.
3. The amino acid contents of the formulation include isoleucine. Is the amino acid composition of crocodile meat meal missing the data of isoleucine in Table 1?
4. Line 213: The market price and Figure 1 should be evaluated with provenance or basis.
5. Line 260: Significantly different (P＞0.05)?
6. The conclusion should be more concise.
Comments for author File: 
Comments.docx
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 2 Report
Review
Paper title: Fishmeal replacement with animal protein source (Crocodylus niloticus meat meal) in diets of Mozambique tilapia (Oreochromis mossambicus) of different size groups
The authors conducted a laboratory study to reveal the effects of fish diets containing Crocodylus niloticus meat meal on the growth performance, feeding, and survival rates in fry and fingerlings of Mozambique tilapia. The authors found that weight gain for all size groups fed commercial diets was significantly higher than that in dif fed formulated diets. The latter, however, resulted in the fry gross feed conversion ratios, fingerling specific growth rates, and survival rates that were similar to commercial diets. Taking into account the lower cost of crocodilian fish meal, this ingredient is concluded to be a promising replacement for fishmeal in diets of cultured Mozambique tilapia.
All these reasons explain the relevance of the paper by Rendani Luthada-Raswiswi and co-authors submitted to "Applied Sciences".
General scores.
The data presented by the authors are original and significant. The study is correctly designed and the authors used appropriate rearing methods. In general, the statistical analyses are performed with good technical standards. The authors conducted careful work that may attract the attention of a wide range of specialists focused on tilapia aquaculture.
Major concerns.
Figure 1. The authors should use graphs with two OY-axes because the weight of feed and cost are measured in different units.
L 357-360. The authors should separate fish and shrimp species in this list.
Specific comments.
L 25. Change “because” to “because of”
L 69. Change “world” to “world's”
L 70. Change “much” to “many”
L 74. Delete “(Ashton, 2010)”
L 86. “Oreochromis mossambicus” should be italicized.
L 100. Change “meat were” to “meat was”
L 103. Change “mesh micron” to “micron mesh”
L 105. Change “rest was” to “rest were”
L 109. Change “described in” to “described in the”
L 114. Change “muffle furnace at 550℃ overnight as described in” to “a muffle furnace at 550°C overnight as described in the”
L 134. Change “University” to “the University”
L 135. Change “Proximate analysis for experimental diets results are in Table 2” to “The results of proximate analysis for experimental diets are presented in Table 2”
L 142. Change “acclimation period” to “the acclimation period”
L 143. Change “smaller size group was” to “small-sized animals were”
L 149. Change “of (0.07 ±1 g fish -1 )” to “of 0.07 ±1 g fish-1”
L 164. Change “with same” to “with the same”
L 169. Change “fingerlings diets” to “fingerling diets”
L 197. Change “fish dried” to “fish were dried”
L 213. Change “fingerlings” to “for fingerlings”
L 238. Delete “Different superscripts show the differences within the same row in Table 3”
L 250. Change “among” to “between”
L 301. Change “indicate” to “indicates
L 314. Change “Figures 1” to “Figure 1”
L 336. Change “high” to “high concentrations of”
L 357. Change “shrimp’s” to “shrimp”
L 374. Change “were high and was” to “were high and were”
L 395. Change “low” to “lower”
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
All issues are well addressed.
Author Response
Pease see the attachment.
Author Response File: Author Response.doc
